Security are helpful. I saw Placebo at the O2 in December and when things got unneccasrily stupid, a bunch of security came in. The system does work. However, if security are arses, just move to somewhere else where you can see things clearly, because the front row isn't the be all and end all of live gigs!
But there are a few of you who are being ultra ultra defensive, and if that's going to be the attitude, then this is the reaction you'll expect, sadly.