One of my pet peeves in Second Life is TPing into a sim and being absolutely assaulted with greeters, LMs, pop-up messages, notecards, group invites and the like.
I had to chuckle at one sim today though, which did all these and the notecard and pop-up said that they did not allow spamming, group invites or griefing.
The irony of this was not lost on me. But seemed to be lost on them. :)