Um... well really... I can't even make servers, so powerless on Q3, and I would not ban anyone. I too realized that and figured just to not give trust to them, or like make a mini where you can't build. A good strategy I use is to Not let anyone build until they start blaming the guy and he gets frustrated and leaves. Also affective on Toontown, Club Penguin, and WoW, except for the building part.