+ remote_users = remote_users(activity)
+
+ salmon_urls = Enum.map(remote_users, & &1.info.salmon)
+ reachable_urls_metadata = Instances.filter_reachable(salmon_urls)
+ reachable_urls = Map.keys(reachable_urls_metadata)
+
+ remote_users
+ |> Enum.filter(&(&1.info.salmon in reachable_urls))