I guess they are more paranoid in some areas. It could be that 911 has made the WTS more paranoid. One of my JW brothers is an elder in security and they watch for people not dressed like JWs and follow them letting main security know their description. I never minded that because pickpockets, thieves and pedophiles target large groups of people. There were legitimate law enforcement at the facility and they were supposed to alert them to any bad situations. I don't know about other countries but in the US JoeBlow citizen can't be using strong armed tactics on someone unless that person has physically attacked them first or someone else, the "they laid a hand on you first" policy.
I haven't seen or heard or any uproar in the stands. What would they look for? Someone holding up a sign, "Down with Ted?" "Pedophiles are here." Actually, it would be counter-productive and I would find it hard to think that any ex-JW who wants to make a real statement would do that. I just gauge that from how my old self would have reacted at the convention to seeing that.
As far as looking for known apostates, I have heard of that, but if they are minding their own business and listening quietly, on what grounds could they make them leave? I would bring friends, a lawyer would be nice. I would just alter my appearance in a way that wasn't attention-getting, temporary hair dye, mustache, dress in JW convention costume, etc. Pretend you are a counter trying to get into a Las Vegas casino.
Also, this occurred to me, are you sure they are security and not just attendants looking for empty seats. Some facilities are extremely crowded and they may be people looking for seats.
These guys are so bored that they look for a problem. I can remember them accosting a bearded man once only to find out that he was one of the administrative staff of the facility. That was good for public relations.
Now I know there are over-zealous goons in some areas that think that God's law supersedes man's in this arena of security. It would be sensible to cooperate if they want you to leave and physical action is threatened. That is why it is good to bring "witnesses" to the action, one with legal experience would be nice.
What a world!
Blondie