G.I. Jane (1997) - Offender: stupid high-schoolers. Crime: talking and laughing during the movie. Our response: an ear-splitting "Shhh!" followed by our very best stink-eye stare-down when they looked over to see who dared tell them to keep it down.
The Core (2003) - Offender: douchebag high-schooler with his dimwit friends. Crime: carrying on a cell phone conversation in the middle of the movie. Our response: a loud "Shut up!" which prompted a fellow moviegoer to add in a "Can you get off the phone?!" They did and then we spent the rest of the movie wondering where in the parking lot the retribution beatdown would happen.
The lesson to us: only go to movies in...
1. An empty theater (first show on a weekday, preferably) so you can sit as far away as possible from your fellow loathsome humans. They cannot be trusted.
2. A 100% sold out theater (opening weekend evenings) so that the dull murmur of the hundreds of people will drown out the more asinine moviegoers. There's also a peer-pressure in effect: when someone's a jerk, it won't fall only on your shoulders to enforce civility.