Its a similar problem faced by our teachers. How to prevent us all from waging frag fests on our LAN in our computer lab. Most of the time, they delete the files or send us netsend messages while in midst of a furious firefight. Infact they have gone to the extent of disbaling the CD drives so that we wont be able to install any games. So for the time being, we haveo make do with online Java bsaed games. Or those small games that we had hidden in our server!
Like enoo said, "gamers will find a way"!