You could have done as I have during one of my last finals I remember.
This was a room full with something like 300 people. We're "happily" working when one of the students starts making very loud noise, and then he turned to the neighbor behind him (a very nice little old lady) and started speaking o.O .
He even went out several times, without consulting anyone, of course. At some point, while he was out I raised my hand, asked the person who was watching us if there wasn't anything we could do.
She replied... and I'm not joking here "Well, you could always go at it together and strangle him. Or something like that." They couldn't do a darn thing themselves, cause, had they called security, the guy could have sued for assault!!!
The worst thing is, we knew the guy was an extremist Islamist or something to that extent... He was always talking of going to bomb buildings, going to Afghanistan to learn about techniques, and was veeeeeeeeeeery creepy in general.