They are called invigilators, and they are there because students cheat on exams. They catch quite a few of them every year. I recall in my first year, I'm in the computer lab, writing up some computer code to simulate a supermarket queuing system. This hot chick sits next to me and starts flirting away, all hot like. I am totally taken in by this behavior. I go off to the bathroom, and hot chick steals my printouts. Bitch stole my fucking code like a whore steals your wallet. I didn't turn her in. The code was unfinished. Instead I wrote new code from scratch with a fully working debugged program, and got an A. Never saw her thieving whore ass again. She probably died of aids.