   end
 
   @doc """
-  A [function plug](https://hexdocs.pm/plug/readme.html#the-plug-conn-struct) used within a
-  router or controller that verifies that there is a currently logged in user.
+  Verifies that the currently logged in user is a site admin.
+
+  Raises `AtomTweaksWeb.ForbiddenUserError` when the current user is not a site admin.
 
   ## Examples
 

  plug :ensure_site_admin when action in [:create]
  ```
  """
  def ensure_site_admin(conn, _) do
    if conn.assigns[:current_user].site_admin do
      conn

  plug :ensure_authenticated_user when action in [:create]
  ```
  """
  @spec ensure_authenticated_user(Plug.Conn.t(), Map.t()) :: Plug.Conn.t() | no_return
  def ensure_authenticated_user(conn, options)

  def ensure_authenticated_user(conn, _) do
    case conn.assigns[:current_user] do
      nil -> raise(NotLoggedInError, conn: conn)
