Now and then I receive an email notification that someone has requested membership to one of the closed communities I mod. They're small groups; one could even call them exclusive, if one wanted to sound fancy pants special. Black tie only. Tut tut.
Thus far the spam has all been from Russian "users"*. Once, due to my own negligence in checking all settings, someone managed to post in one of the communities. They couldn't view it afterwards though as I did set that properly.
It's very satisfying deleting and banning such spammers, and in my head I imagine explosions or a giant mallet coming down on them at their computer. SMOOSH! Like in the cartoons, it leaves them flattened and scuttling around crablike.