When I was looking for legal information, all I saw was about the Philadelphia flash mobs, not about the ones you see on Youtube all of the time, but I fould some agreements for people who are joining a flash mob, and I will have to make something like that or have a post and whatever way I tell people, give them that site and say if you show up, you agree to the terms. I also read about special mall insurance? I've never heard of that, but I will have to be wary of it. Tomorrow I want to look more into the violent and robbing flash mobs.