There's a mute option, but not a block option.

Anyway, the mute option doesn't work like it does on other networks. If I mute someone, for example, it prevents me from seeing them, but it doesn't prevent that user from seeing me. It's supposed to work so they can't see me either, but it doesn't.

Muting works best in communities. If I mute someone in a community, that user can't post or comment, but they can see the posts and can also vote or downvote.

In any case, it would be a good idea to be able to block users who are harmful to us, and for the blocking to be bidirectional.