You know instance admins can read your direct messages in the fediverse? Twitter and Facebook also can - and sometimes do - read your private messages, and they have infrastructure to comply with law enforcement requests. I'd love to see some end-to-end encryption built into Mastodon clients.
@auerbach @micahflee You could run your own instance. But all in all Mastodon doesn't seem to be well-suited for private communication, that's not the niche it fills. There are plenty of other projects for that.