If you encounter issues accessing http://twitter.activitypub.actor/, I am aware of that. I am receiving 40k hits per minute on my server that kind of "DDOS it".
The hits are coming from #Mastodon instances. Mastodon admins should see a lot of 307 errors, in a consequence. Sorry... #MastodonAdmin
Follow the track here : https://framagit.org/DavidLibeau/activitypubactor/issues/11