How do I stop someone contacting me?

Block them, from their profile. A blocked person cannot message you or send you a friend request, and you stop seeing them. Everyone you have blocked is listed under Account → Blocked, where you can unblock them again.

Blocking is quiet and immediate, and it is the right first move — you do not have to justify it to anyone.

If someone is harassing you, threatening you or targeting you across several accounts, block them and report it to us with the details. Blocking protects you; reporting is how it gets dealt with.