diff --git a/lib/pleroma/PasswordResetToken.ex b/lib/pleroma/PasswordResetToken.ex
index 1dccdadae..c3c0384d2 100644
--- a/lib/pleroma/PasswordResetToken.ex
+++ b/lib/pleroma/PasswordResetToken.ex
@@ -10,7 +10,7 @@ defmodule Pleroma.PasswordResetToken do
   alias Pleroma.{User, PasswordResetToken, Repo}
 
   schema "password_reset_tokens" do
-    belongs_to(:user, User)
+    belongs_to(:user, User, type: Pleroma.FlakeId)
     field(:token, :string)
     field(:used, :boolean, default: false)
 
diff --git a/lib/pleroma/activity.ex b/lib/pleroma/activity.ex
index cd61f6ac8..f0aa3ce97 100644
--- a/lib/pleroma/activity.ex
+++ b/lib/pleroma/activity.ex
@@ -8,6 +8,7 @@ defmodule Pleroma.Activity do
   import Ecto.Query
 
   @type t :: %__MODULE__{}
+  @primary_key {:id, Pleroma.FlakeId, autogenerate: true}
 
   # https://github.com/tootsuite/mastodon/blob/master/app/models/notification.rb#L19
   @mastodon_notification_types %{
diff --git a/lib/pleroma/application.ex b/lib/pleroma/application.ex
index ad2797209..47c0e5b68 100644
--- a/lib/pleroma/application.ex
+++ b/lib/pleroma/application.ex
@@ -99,6 +99,7 @@ defmodule Pleroma.Application do
           ],
           id: :cachex_idem
         ),
+        worker(Pleroma.FlakeId, []),
         worker(Pleroma.Web.Federator.RetryQueue, []),
         worker(Pleroma.Web.Federator, []),
         worker(Pleroma.Stats, []),
diff --git a/lib/pleroma/clippy.ex b/lib/pleroma/clippy.ex
new file mode 100644
index 000000000..4e9bdbe19
--- /dev/null
+++ b/lib/pleroma/clippy.ex
@@ -0,0 +1,155 @@
+# Pleroma: A lightweight social networking server
+# Copyright © 2017-2019 Pleroma Authors <https://pleroma.social/>
+# SPDX-License-Identifier: AGPL-3.0-only
+
+defmodule Pleroma.Clippy do
+  @moduledoc false
+  # No software is complete until they have a Clippy implementation.
+  # A ballmer peak _may_ be required to change this module.
+
+  def tip() do
+    tips()
+    |> Enum.random()
+    |> puts()
+  end
+
+  def tips() do
+    host = Pleroma.Config.get([Pleroma.Web.Endpoint, :url, :host])
+
+    [
+      "“πλήρωμα” is “pleroma” in greek",
+      "For an extended Pleroma Clippy Experience, use the “Redmond” themes in Pleroma FE settings",
+      "Staff accounts and MRF policies of Pleroma instances are disclosed on the NodeInfo endpoints for easy transparency!\n
+- https://catgirl.science/misc/nodeinfo.lua?#{host}
+- https://fediverse.network/#{host}/federation",
+      "Pleroma can federate to the Dark Web!\n
+- Tor: https://git.pleroma.social/pleroma/pleroma/wikis/Easy%20Onion%20Federation%20(Tor)
+- i2p: https://git.pleroma.social/pleroma/pleroma/wikis/I2p%20federation",
+      "Lists of Pleroma instances:\n\n- http://distsn.org/pleroma-instances.html\n- https://fediverse.network/pleroma\n- https://the-federation.info/pleroma",
+      "Pleroma uses the LitePub protocol - https://litepub.social",
+      "To receive more federated posts, subscribe to relays!\n
+- How-to: https://git.pleroma.social/pleroma/pleroma/wikis/Admin%20tasks#relay-managment
+- Relays: https://fediverse.network/activityrelay"
+    ]
+  end
+
+  @spec puts(String.t() | [[IO.ANSI.ansicode() | String.t(), ...], ...]) :: nil
+  def puts(text_or_lines) do
+    import IO.ANSI
+
+    lines =
+      if is_binary(text_or_lines) do
+        String.split(text_or_lines, ~r/\n/)
+      else
+        text_or_lines
+      end
+
+    longest_line_size =
+      lines
+      |> Enum.map(&charlist_count_text/1)
+      |> Enum.sort(&>=/2)
+      |> List.first()
+
+    pad_text = longest_line_size
+
+    pad =
+      for(_ <- 1..pad_text, do: "_")
+      |> Enum.join("")
+
+    pad_spaces =
+      for(_ <- 1..pad_text, do: " ")
+      |> Enum.join("")
+
+    spaces = "      "
+
+    pre_lines = [
+      "  /  \\#{spaces}  _#{pad}___",
+      "  |  |#{spaces} / #{pad_spaces}   \\"
+    ]
+
+    for l <- pre_lines do
+      IO.puts(l)
+    end
+
+    clippy_lines = [
+      "  #{bright()}@  @#{reset()}#{spaces} ",
+      "  || ||#{spaces}",
+      "  || ||   <--",
+      "  |\\_/|      ",
+      "  \\___/      "
+    ]
+
+    noclippy_line = "             "
+
+    env = %{
+      max_size: pad_text,
+      pad: pad,
+      pad_spaces: pad_spaces,
+      spaces: spaces,
+      pre_lines: pre_lines,
+      noclippy_line: noclippy_line
+    }
+
+    # surrond one/five line clippy with blank lines around to not fuck up the layout
+    #
+    # yes this fix sucks but it's good enough, have you ever seen a release of windows wihtout some butched
+    # features anyway?
+    lines =
+      if length(lines) == 1 or length(lines) == 5 do
+        [""] ++ lines ++ [""]
+      else
+        lines
+      end
+
+    clippy_line(lines, clippy_lines, env)
+  rescue
+    e ->
+      IO.puts("(Clippy crashed, sorry: #{inspect(e)})")
+      IO.puts(text_or_lines)
+  end
+
+  defp clippy_line([line | lines], [prefix | clippy_lines], env) do
+    IO.puts([prefix <> "| ", rpad_line(line, env.max_size)])
+    clippy_line(lines, clippy_lines, env)
+  end
+
+  # more text lines but clippy's complete
+  defp clippy_line([line | lines], [], env) do
+    IO.puts([env.noclippy_line, "| ", rpad_line(line, env.max_size)])
+
+    if lines == [] do
+      IO.puts(env.noclippy_line <> "\\_#{env.pad}___/")
+    end
+
+    clippy_line(lines, [], env)
+  end
+
+  # no more text lines but clippy's not complete
+  defp clippy_line([], [clippy | clippy_lines], env) do
+    if env.pad do
+      IO.puts(clippy <> "\\_#{env.pad}___/")
+      clippy_line([], clippy_lines, %{env | pad: nil})
+    else
+      IO.puts(clippy)
+      clippy_line([], clippy_lines, env)
+    end
+  end
+
+  defp clippy_line(_, _, _) do
+  end
+
+  defp rpad_line(line, max) do
+    pad = max - (charlist_count_text(line) - 2)
+    pads = Enum.join(for(_ <- 1..pad, do: " "))
+    [IO.ANSI.format(line), pads <> " |"]
+  end
+
+  defp charlist_count_text(line) do
+    if is_list(line) do
+      text = Enum.join(Enum.filter(line, &is_binary/1))
+      String.length(text)
+    else
+      String.length(line)
+    end
+  end
+end
diff --git a/lib/pleroma/filter.ex b/lib/pleroma/filter.ex
index df5374a5c..308bd70e1 100644
--- a/lib/pleroma/filter.ex
+++ b/lib/pleroma/filter.ex
@@ -8,7 +8,7 @@ defmodule Pleroma.Filter do
   alias Pleroma.{User, Repo}
 
   schema "filters" do
-    belongs_to(:user, User)
+    belongs_to(:user, User, type: Pleroma.FlakeId)
     field(:filter_id, :integer)
     field(:hide, :boolean, default: false)
     field(:whole_word, :boolean, default: true)
diff --git a/lib/pleroma/flake_id.ex b/lib/pleroma/flake_id.ex
new file mode 100644
index 000000000..26399ae05
--- /dev/null
+++ b/lib/pleroma/flake_id.ex
@@ -0,0 +1,183 @@
+# Pleroma: A lightweight social networking server
+# Copyright © 2017-2019 Pleroma Authors <https://pleroma.social/>
+# SPDX-License-Identifier: AGPL-3.0-only
+
+defmodule Pleroma.FlakeId do
+  @moduledoc """
+  Flake is a decentralized, k-ordered id generation service.
+
+  Adapted from:
+
+  * [flaky](https://github.com/nirvana/flaky), released under the terms of the Truly Free License,
+  * [Flake](https://github.com/boundary/flake), Copyright 2012, Boundary, Apache License, Version 2.0
+  """
+
+  @type t :: binary
+
+  @behaviour Ecto.Type
+  use GenServer
+  require Logger
+  alias __MODULE__
+  import Kernel, except: [to_string: 1]
+
+  defstruct node: nil, time: 0, sq: 0
+
+  @doc "Converts a binary Flake to a String"
+  def to_string(<<0::integer-size(64), id::integer-size(64)>>) do
+    Kernel.to_string(id)
+  end
+
+  def to_string(flake = <<_::integer-size(64), _::integer-size(48), _::integer-size(16)>>) do
+    encode_base62(flake)
+  end
+
+  def to_string(s), do: s
+
+  for i <- [-1, 0] do
+    def from_string(unquote(i)), do: <<0::integer-size(128)>>
+    def from_string(unquote(Kernel.to_string(i))), do: <<0::integer-size(128)>>
+  end
+
+  def from_string(flake = <<_::integer-size(128)>>), do: flake
+
+  def from_string(string) when is_binary(string) and byte_size(string) < 18 do
+    case Integer.parse(string) do
+      {id, _} -> <<0::integer-size(64), id::integer-size(64)>>
+      _ -> nil
+    end
+  end
+
+  def from_string(string) do
+    string |> decode_base62 |> from_integer
+  end
+
+  def to_integer(<<integer::integer-size(128)>>), do: integer
+
+  def from_integer(integer) do
+    <<_time::integer-size(64), _node::integer-size(48), _seq::integer-size(16)>> =
+      <<integer::integer-size(128)>>
+  end
+
+  @doc "Generates a Flake"
+  @spec get :: binary
+  def get, do: to_string(:gen_server.call(:flake, :get))
+
+  # -- Ecto.Type API
+  @impl Ecto.Type
+  def type, do: :uuid
+
+  @impl Ecto.Type
+  def cast(value) do
+    {:ok, FlakeId.to_string(value)}
+  end
+
+  @impl Ecto.Type
+  def load(value) do
+    {:ok, FlakeId.to_string(value)}
+  end
+
+  @impl Ecto.Type
+  def dump(value) do
+    {:ok, FlakeId.from_string(value)}
+  end
+
+  def autogenerate(), do: get()
+
+  # -- GenServer API
+  def start_link do
+    :gen_server.start_link({:local, :flake}, __MODULE__, [], [])
+  end
+
+  @impl GenServer
+  def init([]) do
+    {:ok, %FlakeId{node: mac(), time: time()}}
+  end
+
+  @impl GenServer
+  def handle_call(:get, _from, state) do
+    {flake, new_state} = get(time(), state)
+    {:reply, flake, new_state}
+  end
+
+  # Matches when the calling time is the same as the state time. Incr. sq
+  defp get(time, %FlakeId{time: time, node: node, sq: seq}) do
+    new_state = %FlakeId{time: time, node: node, sq: seq + 1}
+    {gen_flake(new_state), new_state}
+  end
+
+  # Matches when the times are different, reset sq
+  defp get(newtime, %FlakeId{time: time, node: node}) when newtime > time do
+    new_state = %FlakeId{time: newtime, node: node, sq: 0}
+    {gen_flake(new_state), new_state}
+  end
+
+  # Error when clock is running backwards
+  defp get(newtime, %FlakeId{time: time}) when newtime < time do
+    {:error, :clock_running_backwards}
+  end
+
+  defp gen_flake(%FlakeId{time: time, node: node, sq: seq}) do
+    <<time::integer-size(64), node::integer-size(48), seq::integer-size(16)>>
+  end
+
+  defp nthchar_base62(n) when n <= 9, do: ?0 + n
+  defp nthchar_base62(n) when n <= 35, do: ?A + n - 10
+  defp nthchar_base62(n), do: ?a + n - 36
+
+  defp encode_base62(<<integer::integer-size(128)>>) do
+    integer
+    |> encode_base62([])
+    |> List.to_string()
+  end
+
+  defp encode_base62(int, acc) when int < 0, do: encode_base62(-int, acc)
+  defp encode_base62(int, []) when int == 0, do: '0'
+  defp encode_base62(int, acc) when int == 0, do: acc
+
+  defp encode_base62(int, acc) do
+    r = rem(int, 62)
+    id = div(int, 62)
+    acc = [nthchar_base62(r) | acc]
+    encode_base62(id, acc)
+  end
+
+  defp decode_base62(s) do
+    decode_base62(String.to_charlist(s), 0)
+  end
+
+  defp decode_base62([c | cs], acc) when c >= ?0 and c <= ?9,
+    do: decode_base62(cs, 62 * acc + (c - ?0))
+
+  defp decode_base62([c | cs], acc) when c >= ?A and c <= ?Z,
+    do: decode_base62(cs, 62 * acc + (c - ?A + 10))
+
+  defp decode_base62([c | cs], acc) when c >= ?a and c <= ?z,
+    do: decode_base62(cs, 62 * acc + (c - ?a + 36))
+
+  defp decode_base62([], acc), do: acc
+
+  defp time do
+    {mega_seconds, seconds, micro_seconds} = :erlang.timestamp()
+    1_000_000_000 * mega_seconds + seconds * 1000 + :erlang.trunc(micro_seconds / 1000)
+  end
+
+  def mac do
+    {:ok, addresses} = :inet.getifaddrs()
+
+    macids =
+      Enum.reduce(addresses, [], fn {_iface, attrs}, acc ->
+        case attrs[:hwaddr] do
+          [0, 0, 0 | _] -> acc
+          mac when is_list(mac) -> [mac_to_worker_id(mac) | acc]
+          _ -> acc
+        end
+      end)
+
+    List.first(macids)
+  end
+
+  def mac_to_worker_id(mac) do
+    <<worker::integer-size(48)>> = :binary.list_to_bin(mac)
+    worker
+  end
+end
diff --git a/lib/pleroma/list.ex b/lib/pleroma/list.ex
index a75dc006e..ca66c6916 100644
--- a/lib/pleroma/list.ex
+++ b/lib/pleroma/list.ex
@@ -8,7 +8,7 @@ defmodule Pleroma.List do
   alias Pleroma.{User, Repo, Activity}
 
   schema "lists" do
-    belongs_to(:user, Pleroma.User)
+    belongs_to(:user, User, type: Pleroma.FlakeId)
     field(:title, :string)
     field(:following, {:array, :string}, default: [])
 
diff --git a/lib/pleroma/notification.ex b/lib/pleroma/notification.ex
index c7d01f63b..2c8f60f19 100644
--- a/lib/pleroma/notification.ex
+++ b/lib/pleroma/notification.ex
@@ -9,8 +9,8 @@ defmodule Pleroma.Notification do
 
   schema "notifications" do
     field(:seen, :boolean, default: false)
-    belongs_to(:user, Pleroma.User)
-    belongs_to(:activity, Pleroma.Activity)
+    belongs_to(:user, User, type: Pleroma.FlakeId)
+    belongs_to(:activity, Activity, type: Pleroma.FlakeId)
 
     timestamps()
   end
@@ -96,7 +96,7 @@ defmodule Pleroma.Notification do
     end
   end
 
-  def create_notifications(%Activity{id: _, data: %{"to" => _, "type" => type}} = activity)
+  def create_notifications(%Activity{data: %{"to" => _, "type" => type}} = activity)
       when type in ["Create", "Like", "Announce", "Follow"] do
     users = get_notified_from_activity(activity)
 
diff --git a/lib/pleroma/user.ex b/lib/pleroma/user.ex
index 18137106e..b006f9f19 100644
--- a/lib/pleroma/user.ex
+++ b/lib/pleroma/user.ex
@@ -17,6 +17,8 @@ defmodule Pleroma.User do
 
   @type t :: %__MODULE__{}
 
+  @primary_key {:id, Pleroma.FlakeId, autogenerate: true}
+
   @email_regex ~r/^[a-zA-Z0-9.!#$%&'*+\/=?^_`{|}~-]+@[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?(?:\.[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?)*$/
 
   @strict_local_nickname_regex ~r/^[a-zA-Z\d]+$/
diff --git a/lib/pleroma/user/info.ex b/lib/pleroma/user/info.ex
index fb1791c20..c6c923aac 100644
--- a/lib/pleroma/user/info.ex
+++ b/lib/pleroma/user/info.ex
@@ -31,7 +31,7 @@ defmodule Pleroma.User.Info do
     field(:hub, :string, default: nil)
     field(:salmon, :string, default: nil)
     field(:hide_network, :boolean, default: false)
-    field(:pinned_activities, {:array, :integer}, default: [])
+    field(:pinned_activities, {:array, :string}, default: [])
 
     # Found in the wild
     # ap_id -> Where is this used?
diff --git a/lib/pleroma/web/activity_pub/activity_pub.ex b/lib/pleroma/web/activity_pub/activity_pub.ex
index 82fffd324..85fa83e2b 100644
--- a/lib/pleroma/web/activity_pub/activity_pub.ex
+++ b/lib/pleroma/web/activity_pub/activity_pub.ex
@@ -410,6 +410,8 @@ defmodule Pleroma.Web.ActivityPub.ActivityPub do
     |> Enum.reverse()
   end
 
+  defp restrict_since(query, %{"since_id" => ""}), do: query
+
   defp restrict_since(query, %{"since_id" => since_id}) do
     from(activity in query, where: activity.id > ^since_id)
   end
@@ -465,6 +467,8 @@ defmodule Pleroma.Web.ActivityPub.ActivityPub do
 
   defp restrict_local(query, _), do: query
 
+  defp restrict_max(query, %{"max_id" => ""}), do: query
+
   defp restrict_max(query, %{"max_id" => max_id}) do
     from(activity in query, where: activity.id < ^max_id)
   end
diff --git a/lib/pleroma/web/activity_pub/transmogrifier.ex b/lib/pleroma/web/activity_pub/transmogrifier.ex
index 46b1646f7..6656a11c6 100644
--- a/lib/pleroma/web/activity_pub/transmogrifier.ex
+++ b/lib/pleroma/web/activity_pub/transmogrifier.ex
@@ -900,15 +900,10 @@ defmodule Pleroma.Web.ActivityPub.Transmogrifier do
 
     maybe_retire_websub(user.ap_id)
 
-    # Only do this for recent activties, don't go through the whole db.
-    # Only look at the last 1000 activities.
-    since = (Repo.aggregate(Activity, :max, :id) || 0) - 1_000
-
     q =
       from(
         a in Activity,
         where: ^old_follower_address in a.recipients,
-        where: a.id > ^since,
         update: [
           set: [
             recipients:
diff --git a/lib/pleroma/web/activity_pub/views/user_view.ex b/lib/pleroma/web/activity_pub/views/user_view.ex
index fe8248107..dcf681b6d 100644
--- a/lib/pleroma/web/activity_pub/views/user_view.ex
+++ b/lib/pleroma/web/activity_pub/views/user_view.ex
@@ -160,7 +160,7 @@ defmodule Pleroma.Web.ActivityPub.UserView do
       "partOf" => iri,
       "totalItems" => info.note_count,
       "orderedItems" => collection,
-      "next" => "#{iri}?max_id=#{min_id - 1}"
+      "next" => "#{iri}?max_id=#{min_id}"
     }
 
     if max_qid == nil do
@@ -207,7 +207,7 @@ defmodule Pleroma.Web.ActivityPub.UserView do
       "partOf" => iri,
       "totalItems" => -1,
       "orderedItems" => collection,
-      "next" => "#{iri}?max_id=#{min_id - 1}"
+      "next" => "#{iri}?max_id=#{min_id}"
     }
 
     if max_qid == nil do
diff --git a/lib/pleroma/web/oauth/authorization.ex b/lib/pleroma/web/oauth/authorization.ex
index cc4b74bc5..f8c65602d 100644
--- a/lib/pleroma/web/oauth/authorization.ex
+++ b/lib/pleroma/web/oauth/authorization.ex
@@ -14,7 +14,7 @@ defmodule Pleroma.Web.OAuth.Authorization do
     field(:token, :string)
     field(:valid_until, :naive_datetime)
     field(:used, :boolean, default: false)
-    belongs_to(:user, Pleroma.User)
+    belongs_to(:user, Pleroma.User, type: Pleroma.FlakeId)
     belongs_to(:app, App)
 
     timestamps()
diff --git a/lib/pleroma/web/oauth/token.ex b/lib/pleroma/web/oauth/token.ex
index f0ebc63f6..4e01b123b 100644
--- a/lib/pleroma/web/oauth/token.ex
+++ b/lib/pleroma/web/oauth/token.ex
@@ -14,7 +14,7 @@ defmodule Pleroma.Web.OAuth.Token do
     field(:token, :string)
     field(:refresh_token, :string)
     field(:valid_until, :naive_datetime)
-    belongs_to(:user, Pleroma.User)
+    belongs_to(:user, Pleroma.User, type: Pleroma.FlakeId)
     belongs_to(:app, App)
 
     timestamps()
diff --git a/lib/pleroma/web/push/subscription.ex b/lib/pleroma/web/push/subscription.ex
index 82b30950c..bd9d9f3a7 100644
--- a/lib/pleroma/web/push/subscription.ex
+++ b/lib/pleroma/web/push/subscription.ex
@@ -10,7 +10,7 @@ defmodule Pleroma.Web.Push.Subscription do
   alias Pleroma.Web.Push.Subscription
 
   schema "push_subscriptions" do
-    belongs_to(:user, User)
+    belongs_to(:user, User, type: Pleroma.FlakeId)
     belongs_to(:token, Token)
     field(:endpoint, :string)
     field(:key_p256dh, :string)
diff --git a/lib/pleroma/web/twitter_api/twitter_api_controller.ex b/lib/pleroma/web/twitter_api/twitter_api_controller.ex
index 8c9060cf2..3064d61ea 100644
--- a/lib/pleroma/web/twitter_api/twitter_api_controller.ex
+++ b/lib/pleroma/web/twitter_api/twitter_api_controller.ex
@@ -265,8 +265,6 @@ defmodule Pleroma.Web.TwitterAPI.Controller do
   end
 
   def fetch_conversation(%{assigns: %{user: user}} = conn, %{"id" => id}) do
-    id = String.to_integer(id)
-
     with context when is_binary(context) <- TwitterAPI.conversation_id_to_context(id),
          activities <-
            ActivityPub.fetch_activities_for_context(context, %{
@@ -340,44 +338,47 @@ defmodule Pleroma.Web.TwitterAPI.Controller do
   end
 
   def favorite(%{assigns: %{user: user}} = conn, %{"id" => id}) do
-    with {_, {:ok, id}} <- {:param_cast, Ecto.Type.cast(:integer, id)},
-         {:ok, activity} <- TwitterAPI.fav(user, id) do
+    with {:ok, activity} <- TwitterAPI.fav(user, id) do
       conn
       |> put_view(ActivityView)
       |> render("activity.json", %{activity: activity, for: user})
+    else
+      _ -> json_reply(conn, 400, Jason.encode!(%{}))
     end
   end
 
   def unfavorite(%{assigns: %{user: user}} = conn, %{"id" => id}) do
-    with {_, {:ok, id}} <- {:param_cast, Ecto.Type.cast(:integer, id)},
-         {:ok, activity} <- TwitterAPI.unfav(user, id) do
+    with {:ok, activity} <- TwitterAPI.unfav(user, id) do
       conn
       |> put_view(ActivityView)
       |> render("activity.json", %{activity: activity, for: user})
+    else
+      _ -> json_reply(conn, 400, Jason.encode!(%{}))
     end
   end
 
   def retweet(%{assigns: %{user: user}} = conn, %{"id" => id}) do
-    with {_, {:ok, id}} <- {:param_cast, Ecto.Type.cast(:integer, id)},
-         {:ok, activity} <- TwitterAPI.repeat(user, id) do
+    with {:ok, activity} <- TwitterAPI.repeat(user, id) do
       conn
       |> put_view(ActivityView)
       |> render("activity.json", %{activity: activity, for: user})
+    else
+      _ -> json_reply(conn, 400, Jason.encode!(%{}))
     end
   end
 
   def unretweet(%{assigns: %{user: user}} = conn, %{"id" => id}) do
-    with {_, {:ok, id}} <- {:param_cast, Ecto.Type.cast(:integer, id)},
-         {:ok, activity} <- TwitterAPI.unrepeat(user, id) do
+    with {:ok, activity} <- TwitterAPI.unrepeat(user, id) do
       conn
       |> put_view(ActivityView)
       |> render("activity.json", %{activity: activity, for: user})
+    else
+      _ -> json_reply(conn, 400, Jason.encode!(%{}))
     end
   end
 
   def pin(%{assigns: %{user: user}} = conn, %{"id" => id}) do
-    with {_, {:ok, id}} <- {:param_cast, Ecto.Type.cast(:integer, id)},
-         {:ok, activity} <- TwitterAPI.pin(user, id) do
+    with {:ok, activity} <- TwitterAPI.pin(user, id) do
       conn
       |> put_view(ActivityView)
       |> render("activity.json", %{activity: activity, for: user})
@@ -388,8 +389,7 @@ defmodule Pleroma.Web.TwitterAPI.Controller do
   end
 
   def unpin(%{assigns: %{user: user}} = conn, %{"id" => id}) do
-    with {_, {:ok, id}} <- {:param_cast, Ecto.Type.cast(:integer, id)},
-         {:ok, activity} <- TwitterAPI.unpin(user, id) do
+    with {:ok, activity} <- TwitterAPI.unpin(user, id) do
       conn
       |> put_view(ActivityView)
       |> render("activity.json", %{activity: activity, for: user})
@@ -556,7 +556,6 @@ defmodule Pleroma.Web.TwitterAPI.Controller do
 
   def approve_friend_request(conn, %{"user_id" => uid} = _params) do
     with followed <- conn.assigns[:user],
-         uid when is_number(uid) <- String.to_integer(uid),
          %User{} = follower <- Repo.get(User, uid),
          {:ok, follower} <- User.maybe_follow(follower, followed),
          %Activity{} = follow_activity <- Utils.fetch_latest_follow(follower, followed),
@@ -578,7 +577,6 @@ defmodule Pleroma.Web.TwitterAPI.Controller do
 
   def deny_friend_request(conn, %{"user_id" => uid} = _params) do
     with followed <- conn.assigns[:user],
-         uid when is_number(uid) <- String.to_integer(uid),
          %User{} = follower <- Repo.get(User, uid),
          %Activity{} = follow_activity <- Utils.fetch_latest_follow(follower, followed),
          {:ok, follow_activity} <- Utils.update_follow_state(follow_activity, "reject"),
diff --git a/lib/pleroma/web/websub/websub_client_subscription.ex b/lib/pleroma/web/websub/websub_client_subscription.ex
index 105b0069f..969ee0684 100644
--- a/lib/pleroma/web/websub/websub_client_subscription.ex
+++ b/lib/pleroma/web/websub/websub_client_subscription.ex
@@ -13,7 +13,7 @@ defmodule Pleroma.Web.Websub.WebsubClientSubscription do
     field(:state, :string)
     field(:subscribers, {:array, :string}, default: [])
     field(:hub, :string)
-    belongs_to(:user, User)
+    belongs_to(:user, User, type: Pleroma.FlakeId)
 
     timestamps()
   end
diff --git a/priv/repo/migrations/20181218172826_users_and_activities_flake_id.exs b/priv/repo/migrations/20181218172826_users_and_activities_flake_id.exs
new file mode 100644
index 000000000..47d2d02da
--- /dev/null
+++ b/priv/repo/migrations/20181218172826_users_and_activities_flake_id.exs
@@ -0,0 +1,125 @@
+defmodule Pleroma.Repo.Migrations.UsersAndActivitiesFlakeId do
+  use Ecto.Migration
+  alias Pleroma.Clippy
+  require Integer
+  import Ecto.Query
+  alias Pleroma.Repo
+
+  # This migrates from int serial IDs to custom Flake:
+  #   1- create a temporary uuid column
+  #   2- fill this column with compatibility ids (see below)
+  #   3- remove pkeys constraints
+  #   4- update relation pkeys with the new ids
+  #   5- rename the temporary column to id
+  #   6- re-create the constraints
+  def change do
+    # Old serial int ids are transformed to 128bits with extra padding.
+    # The application (in `Pleroma.FlakeId`) handles theses IDs properly as integers; to keep compatibility
+    # with previously issued ids.
+    #execute "update activities set external_id = CAST( LPAD( TO_HEX(id), 32, '0' ) AS uuid);"
+    #execute "update users set external_id = CAST( LPAD( TO_HEX(id), 32, '0' ) AS uuid);"
+
+    clippy = start_clippy_heartbeats()
+
+    # Lock both tables to avoid a running server to meddling with our transaction
+    execute "LOCK TABLE activities;"
+    execute "LOCK TABLE users;"
+
+    execute """
+      ALTER TABLE activities
+      DROP CONSTRAINT activities_pkey CASCADE,
+      ALTER COLUMN id DROP default,
+      ALTER COLUMN id SET DATA TYPE uuid USING CAST( LPAD( TO_HEX(id), 32, '0' ) AS uuid),
+      ADD PRIMARY KEY (id);
+    """
+
+    execute """
+    ALTER TABLE users
+    DROP CONSTRAINT users_pkey CASCADE,
+    ALTER COLUMN id DROP default,
+    ALTER COLUMN id SET DATA TYPE uuid USING CAST( LPAD( TO_HEX(id), 32, '0' ) AS uuid),
+    ADD PRIMARY KEY (id);
+    """
+
+    execute "UPDATE users SET info = jsonb_set(info, '{pinned_activities}', array_to_json(ARRAY(select jsonb_array_elements_text(info->'pinned_activities')))::jsonb);"
+
+    # Fkeys:
+    # Activities - Referenced by:
+    #   TABLE "notifications" CONSTRAINT "notifications_activity_id_fkey" FOREIGN KEY (activity_id) REFERENCES activities(id) ON DELETE CASCADE
+    # Users - Referenced by:
+    #  TABLE "filters" CONSTRAINT "filters_user_id_fkey" FOREIGN KEY (user_id) REFERENCES users(id) ON DELETE CASCADE
+    #  TABLE "lists" CONSTRAINT "lists_user_id_fkey" FOREIGN KEY (user_id) REFERENCES users(id) ON DELETE CASCADE
+    #  TABLE "notifications" CONSTRAINT "notifications_user_id_fkey" FOREIGN KEY (user_id) REFERENCES users(id) ON DELETE CASCADE
+    #  TABLE "oauth_authorizations" CONSTRAINT "oauth_authorizations_user_id_fkey" FOREIGN KEY (user_id) REFERENCES users(id)
+    #  TABLE "oauth_tokens" CONSTRAINT "oauth_tokens_user_id_fkey" FOREIGN KEY (user_id) REFERENCES users(id)
+    #  TABLE "password_reset_tokens" CONSTRAINT "password_reset_tokens_user_id_fkey" FOREIGN KEY (user_id) REFERENCES users(id)
+    #  TABLE "push_subscriptions" CONSTRAINT "push_subscriptions_user_id_fkey" FOREIGN KEY (user_id) REFERENCES users(id) ON DELETE CASCADE
+    #  TABLE "websub_client_subscriptions" CONSTRAINT "websub_client_subscriptions_user_id_fkey" FOREIGN KEY (user_id) REFERENCES users(id)
+
+    execute """
+    ALTER TABLE notifications
+    ALTER COLUMN activity_id SET DATA TYPE uuid USING CAST( LPAD( TO_HEX(activity_id), 32, '0' ) AS uuid),
+    ADD CONSTRAINT notifications_activity_id_fkey FOREIGN KEY (activity_id) REFERENCES activities(id) ON DELETE CASCADE;
+    """
+
+    for table <- ~w(notifications filters lists oauth_authorizations oauth_tokens password_reset_tokens push_subscriptions websub_client_subscriptions) do
+      execute """
+      ALTER TABLE #{table}
+      ALTER COLUMN user_id SET DATA TYPE uuid USING CAST( LPAD( TO_HEX(user_id), 32, '0' ) AS uuid),
+      ADD CONSTRAINT #{table}_user_id_fkey FOREIGN KEY (user_id) REFERENCES users(id) ON DELETE CASCADE;
+      """
+    end
+
+    flush()
+
+    stop_clippy_heartbeats(clippy)
+  end
+
+  defp start_clippy_heartbeats() do
+    count = from(a in "activities", select: count(a.id)) |> Repo.one!
+
+    if count > 5000 do
+      heartbeat_interval = :timer.minutes(2) + :timer.seconds(30)
+      all_tips = Clippy.tips() ++ [
+        "The migration is still running, maybe it's time for another “tea”?",
+        "Happy rabbits practice a cute behavior known as a\n“binky:” they jump up in the air\nand twist\nand spin around!",
+        "Nothing and everything.\n\nI still work.",
+        "Pleroma runs on a Raspberry Pi!\n\n  … but this migration will take forever if you\nactually run on a raspberry pi",
+        "Status? Stati? Post? Note? Toot?\nRepeat? Reboost? Boost? Retweet? Retoot??\n\nI-I'm confused.",
+      ]
+
+      heartbeat = fn(heartbeat, runs, all_tips, tips) ->
+        tips = if Integer.is_even(runs) do
+          tips = if tips == [], do: all_tips, else: tips
+          [tip | tips] = Enum.shuffle(tips)
+          Clippy.puts(tip)
+          tips
+        else
+          IO.puts "\n -- #{DateTime.to_string(DateTime.utc_now())} Migration still running, please wait…\n"
+          tips
+        end
+        :timer.sleep(heartbeat_interval)
+        heartbeat.(heartbeat, runs + 1, all_tips, tips)
+      end
+
+      Clippy.puts [
+        [:red, :bright, "It looks like you are running an older instance!"],
+        [""],
+        [:bright, "This migration may take a long time", :reset, " -- so you probably should"],
+        ["go drink a cofe, or a tea, or a beer, a whiskey, a vodka,"],
+        ["while it runs to deal with your temporary fediverse pause!"]
+      ]
+      :timer.sleep(heartbeat_interval)
+      spawn_link(fn() -> heartbeat.(heartbeat, 1, all_tips, []) end)
+    end
+  end
+
+  defp stop_clippy_heartbeats(pid) do
+    if pid do
+      Process.unlink(pid)
+      Process.exit(pid, :kill)
+      Clippy.puts [[:green, :bright, "Hurray!!", "", "", "Migration completed!"]]
+    end
+  end
+
+end
diff --git a/test/flake_id_test.exs b/test/flake_id_test.exs
new file mode 100644
index 000000000..8e969fd1c
--- /dev/null
+++ b/test/flake_id_test.exs
@@ -0,0 +1,41 @@
+# Pleroma: A lightweight social networking server
+# Copyright © 2017-2019 Pleroma Authors <https://pleroma.social/>
+# SPDX-License-Identifier: AGPL-3.0-only
+
+defmodule Pleroma.FlakeIdTest do
+  use Pleroma.DataCase
+  import Kernel, except: [to_string: 1]
+  import Pleroma.FlakeId
+
+  describe "fake flakes (compatibility with older serial integers)" do
+    test "from_string/1" do
+      fake_flake = <<0::integer-size(64), 42::integer-size(64)>>
+      assert from_string("42") == fake_flake
+    end
+
+    test "zero or -1 is a null flake" do
+      fake_flake = <<0::integer-size(128)>>
+      assert from_string("0") == fake_flake
+      assert from_string("-1") == fake_flake
+    end
+
+    test "to_string/1" do
+      fake_flake = <<0::integer-size(64), 42::integer-size(64)>>
+      assert to_string(fake_flake) == "42"
+    end
+  end
+
+  test "ecto type behaviour" do
+    flake = <<0, 0, 1, 104, 80, 229, 2, 235, 140, 22, 69, 201, 53, 210, 0, 0>>
+    flake_s = "9eoozpwTul5mjSEDRI"
+
+    assert cast(flake) == {:ok, flake_s}
+    assert cast(flake_s) == {:ok, flake_s}
+
+    assert load(flake) == {:ok, flake_s}
+    assert load(flake_s) == {:ok, flake_s}
+
+    assert dump(flake_s) == {:ok, flake}
+    assert dump(flake) == {:ok, flake}
+  end
+end
diff --git a/test/web/twitter_api/twitter_api_controller_test.exs b/test/web/twitter_api/twitter_api_controller_test.exs
index f22cdd870..863abd10f 100644
--- a/test/web/twitter_api/twitter_api_controller_test.exs
+++ b/test/web/twitter_api/twitter_api_controller_test.exs
@@ -797,7 +797,7 @@ defmodule Pleroma.Web.TwitterAPI.ControllerTest do
         |> with_credentials(current_user.nickname, "test")
         |> post("/api/favorites/create/1.json")
 
-      assert json_response(conn, 500)
+      assert json_response(conn, 400)
     end
   end
 
@@ -1621,7 +1621,7 @@ defmodule Pleroma.Web.TwitterAPI.ControllerTest do
       conn =
         build_conn()
         |> assign(:user, user)
-        |> post("/api/pleroma/friendships/approve", %{"user_id" => to_string(other_user.id)})
+        |> post("/api/pleroma/friendships/approve", %{"user_id" => other_user.id})
 
       assert relationship = json_response(conn, 200)
       assert other_user.id == relationship["id"]
@@ -1644,7 +1644,7 @@ defmodule Pleroma.Web.TwitterAPI.ControllerTest do
       conn =
         build_conn()
         |> assign(:user, user)
-        |> post("/api/pleroma/friendships/deny", %{"user_id" => to_string(other_user.id)})
+        |> post("/api/pleroma/friendships/deny", %{"user_id" => other_user.id})
 
       assert relationship = json_response(conn, 200)
       assert other_user.id == relationship["id"]