Unsubscribe from their feed. I'd personally unfriend them, too.

Can you stay off of facebook? Change your feed so that you only see things from "safe" people?

I don't really "do" facebook anymore although I do have an account still. I keep it b/c its a link to people from my past if I should ever so desire to communicate with them. Its annoying how they want to communicate with me though----and I don't want to talk to them, lol.