I had a stalker the other day (claiming to be an 11yo boy, though that seemed entirely improbable), who at one point said s/he was going to keep pinging me until I came to their party... though they eventually went away after being ignored.
Alas, this makes me wonder if there needs to be some rules or guidelines for behavior and what constitutes "unacceptable", and whether there needs to be a way to report players who violate the guidelines.