Well I dunno if it's my upbringing or New Zealand or what, but I started playing PlaneShift at the age of 14 and have only had little arguments with various players.
As soon as I started playing PlaneShift the first thing my brother showed me was the /report [player name] command, which I have used to players who have been harassing me, or just acting OOC. I suppose if you report plenty of players, you'd get a reputation of reporting bad behaviour?
Other than that, if they don't have a facebook account. Which honestly I've seen far worse on there. Then they're too young to play Planeshift, especially at the age of 10. Tell them to go climb a tree or something 'kids' did in the late 90s'.