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diff --git a/lib/pleroma/web/activity_pub/mrf/hashtag_policy.ex b/lib/pleroma/web/activity_pub/mrf/hashtag_policy.ex
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+++ b/lib/pleroma/web/activity_pub/mrf/hashtag_policy.ex
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+# Pleroma: A lightweight social networking server
+# Copyright © 2017-2021 Pleroma Authors <https://pleroma.social/>
+# SPDX-License-Identifier: AGPL-3.0-only
+
+defmodule Pleroma.Web.ActivityPub.MRF.HashtagPolicy do
+  require Pleroma.Constants
+
+  alias Pleroma.Config
+  alias Pleroma.Object
+
+  @moduledoc """
+  Reject, TWKN-remove or Set-Sensitive messsages with specific hashtags (without the leading #)
+
+  Note: This MRF Policy is always enabled, if you want to disable it you have to set empty lists.
+  """
+
+  @behaviour Pleroma.Web.ActivityPub.MRF.Policy
+
+  defp check_reject(message, hashtags) do
+    if Enum.any?(Config.get([:mrf_hashtag, :reject]), fn match -> match in hashtags end) do
+      {:reject, "[HashtagPolicy] Matches with rejected keyword"}
+    else
+      {:ok, message}
+    end
+  end
+
+  defp check_ftl_removal(%{"to" => to} = message, hashtags) do
+    if Pleroma.Constants.as_public() in to and
+         Enum.any?(Config.get([:mrf_hashtag, :federated_timeline_removal]), fn match ->
+           match in hashtags
+         end) do
+      to = List.delete(to, Pleroma.Constants.as_public())
+      cc = [Pleroma.Constants.as_public() | message["cc"] || []]
+
+      message =
+        message
+        |> Map.put("to", to)
+        |> Map.put("cc", cc)
+        |> Kernel.put_in(["object", "to"], to)
+        |> Kernel.put_in(["object", "cc"], cc)
+
+      {:ok, message}
+    else
+      {:ok, message}
+    end
+  end
+
+  defp check_ftl_removal(message, _hashtags), do: {:ok, message}
+
+  defp check_sensitive(message, hashtags) do
+    if Enum.any?(Config.get([:mrf_hashtag, :sensitive]), fn match -> match in hashtags end) do
+      {:ok, Kernel.put_in(message, ["object", "sensitive"], true)}
+    else
+      {:ok, message}
+    end
+  end
+
+  @impl true
+  def filter(%{"type" => "Create", "object" => object} = message) do
+    hashtags = Object.hashtags(%Object{data: object})
+
+    if hashtags != [] do
+      with {:ok, message} <- check_reject(message, hashtags),
+           {:ok, message} <- check_ftl_removal(message, hashtags),
+           {:ok, message} <- check_sensitive(message, hashtags) do
+        {:ok, message}
+      end
+    else
+      {:ok, message}
+    end
+  end
+
+  @impl true
+  def filter(message), do: {:ok, message}
+
+  @impl true
+  def describe do
+    mrf_hashtag =
+      Config.get(:mrf_hashtag)
+      |> Enum.into(%{})
+
+    {:ok, %{mrf_hashtag: mrf_hashtag}}
+  end
+
+  @impl true
+  def config_description do
+    %{
+      key: :mrf_hashtag,
+      related_policy: "Pleroma.Web.ActivityPub.MRF.HashtagPolicy",
+      label: "MRF Hashtag",
+      description: @moduledoc,
+      children: [
+        %{
+          key: :reject,
+          type: {:list, :string},
+          description: "A list of hashtags which result in message being rejected.",
+          suggestions: ["foo"]
+        },
+        %{
+          key: :federated_timeline_removal,
+          type: {:list, :string},
+          description:
+            "A list of hashtags which result in message being removed from federated timelines (a.k.a unlisted).",
+          suggestions: ["foo"]
+        },
+        %{
+          key: :sensitive,
+          type: {:list, :string},
+          description:
+            "A list of hashtags which result in message being set as sensitive (a.k.a NSFW/R-18)",
+          suggestions: ["nsfw", "r18"]
+        }
+      ]
+    }
+  end
+end