Recent Ex, Yep, Unfriend, and Block....
Although I am FB friends with some past girlfriends just to remind myself how fat and homely they have become....
Had a woman who had approached me and been flirty who turned bitchy on me when I became available. Didn't even tell her she was banished, just blocked and unfriended her after she sent me a critical and insulting message. I don't deserve to be treated that way and I won't allow her to do that to me.
Block and unfriend also guards against the potential nasty message to people you actually care about. Cut off the branch before the Rot spreads.