Edited on Thu Aug-06-09 02:40 PM by MineralMan
I suggest this in all seriousness. It works. I have done it in other circumstances.
First, you have to be a guy to pull this off. Dress in a very conservative dark suit with a simple tie. Have a Bluetooth headset in one ear. Carry a good camera with a telephoto lens. At the meeting, photograph the berserkers and rabble rousers. Do it openly and obviously. You can actually take photos or not...it doesn't matter. Appear to be talking as you work.
Be visible and obvious at all times, scanning the crowd and only photograph disruptors. Don't use flash equipment. Everyone knows that the alphabet agencies can shoot in low light.
Stay with the crowd. Do not go alone outside the meeting place until you have someone there to accompany you.
What will happen is that the disruptors will see you taking photos and assume you are some sort of law enforcement person. Many will be intimidated enough to shut up. Others will simply not act out.
You will make no friends doing this, but you'll slow the meeting down.
It's an old strategy, but very effective.