There is no other choice other then to accept friend request. When somebody wants to write you in private chat he/she can't do that until they are friends of you. So I need to accept all friend requests to allow such possibility. But after some time I discovered, that friends post nonverified antiscientific information like this - https://asgardia.space/en/blog/24566-a-39time-traveler39-says-he-returned-from-the-year-5000-and-has-bad-news/ or that - https://asgardia.space/en/blog/23413-red-people-can-be-de-facto-asgardians/

I want to be able to unfriend such people to not read such things. But see no UI elements in the interface of this site.

I am looking for this option too. If you ''ll know it some day, please share it with me. No body in forum or support can answer me how to kick off some freaks.

If a time traveler comes back from the year 5000 with bad news.  I would consider it a scientific impeeritive to at least give his story a listen.