diff --git a/lib/pleroma/web/activity_pub/mrf/anti_followbot_policy.ex b/lib/pleroma/web/activity_pub/mrf/anti_followbot_policy.ex
new file mode 100644
index 000000000..7c6ad582a
--- /dev/null
+++ b/lib/pleroma/web/activity_pub/mrf/anti_followbot_policy.ex
@@ -0,0 +1,57 @@
+# Pleroma: A lightweight social networking server
+# Copyright © 2019 Pleroma Authors
+# SPDX-License-Identifier: AGPL-3.0-only
+
+defmodule Pleroma.Web.ActivityPub.MRF.AntiFollowbotPolicy do
+ alias Pleroma.User
+
+ @behaviour Pleroma.Web.ActivityPub.MRF
+
+ # XXX: this should become User.normalize_by_ap_id() or similar, really.
+ defp normalize_by_ap_id(%{"id" => id}), do: User.get_cached_by_ap_id(id)
+ defp normalize_by_ap_id(uri) when is_binary(uri), do: User.get_cached_by_ap_id(uri)
+ defp normalize_by_ap_id(_), do: nil
+
+ defp score_nickname("followbot@" <> _), do: 1.0
+ defp score_nickname("federationbot@" <> _), do: 1.0
+ defp score_nickname("federation_bot@" <> _), do: 1.0
+ defp score_nickname(_), do: 0.0
+
+ defp score_displayname("federation bot"), do: 1.0
+ defp score_displayname("federationbot"), do: 1.0
+ defp score_displayname("fedibot"), do: 1.0
+ defp score_displayname(_), do: 0.0
+
+ defp determine_if_followbot(%User{nickname: nickname, name: displayname}) do
+ nick_score =
+ nickname
+ |> String.downcase()
+ |> score_nickname()
+
+ name_score =
+ displayname
+ |> String.downcase()
+ |> score_displayname()
+
+ nick_score + name_score
+ end
+
+ defp determine_if_followbot(_), do: 0.0
+
+ @impl true
+ def filter(%{"type" => "Follow", "actor" => actor_id} = message) do
+ %User{} = actor = normalize_by_ap_id(actor_id)
+
+ score = determine_if_followbot(actor)
+
+ # TODO: scan biography data for keywords and score it somehow.
+ if score < 0.8 do
+ {:ok, message}
+ else
+ {:reject, nil}
+ end
+ end
+
+ @impl true
+ def filter(message), do: {:ok, message}
+end
diff --git a/test/web/activity_pub/mrf/anti_followbot_policy_test.exs b/test/web/activity_pub/mrf/anti_followbot_policy_test.exs
new file mode 100644
index 000000000..2ea4f9d3f
--- /dev/null
+++ b/test/web/activity_pub/mrf/anti_followbot_policy_test.exs
@@ -0,0 +1,57 @@
+# Pleroma: A lightweight social networking server
+# Copyright © 2019 Pleroma Authors
+# SPDX-License-Identifier: AGPL-3.0-only
+
+defmodule Pleroma.Web.ActivityPub.MRF.AntiFollowbotPolicyTest do
+ use Pleroma.DataCase
+ import Pleroma.Factory
+
+ alias Pleroma.Web.ActivityPub.MRF.AntiFollowbotPolicy
+
+ describe "blocking based on attributes" do
+ test "matches followbots by nickname" do
+ actor = insert(:user, %{nickname: "followbot@example.com"})
+ target = insert(:user)
+
+ message = %{
+ "@context" => "https://www.w3.org/ns/activitystreams",
+ "type" => "Follow",
+ "actor" => actor.ap_id,
+ "object" => target.ap_id,
+ "id" => "https://example.com/activities/1234"
+ }
+
+ {:reject, nil} = AntiFollowbotPolicy.filter(message)
+ end
+
+ test "matches followbots by display name" do
+ actor = insert(:user, %{name: "Federation Bot"})
+ target = insert(:user)
+
+ message = %{
+ "@context" => "https://www.w3.org/ns/activitystreams",
+ "type" => "Follow",
+ "actor" => actor.ap_id,
+ "object" => target.ap_id,
+ "id" => "https://example.com/activities/1234"
+ }
+
+ {:reject, nil} = AntiFollowbotPolicy.filter(message)
+ end
+ end
+
+ test "it allows non-followbots" do
+ actor = insert(:user)
+ target = insert(:user)
+
+ message = %{
+ "@context" => "https://www.w3.org/ns/activitystreams",
+ "type" => "Follow",
+ "actor" => actor.ap_id,
+ "object" => target.ap_id,
+ "id" => "https://example.com/activities/1234"
+ }
+
+ {:ok, _} = AntiFollowbotPolicy.filter(message)
+ end
+end