I don't think the event can, but the hotel can have it's own rules, which again have varying degrees of legality according to state. A least, that's AC's
excuse. That being said, I don't think this is so muchso a fact that someone carries as someone may being doing so for non-personal reasons of a security nature... which is fucktarded unless your guarding a bank or equivalent. If you are in the con hotel, and don't plan to travel at night... that's pretty pointless. I'd personally rather see a frown on it for everyone, than have hot heads like Jimbo ready to blast a cap in someone. All politics aside, the things are rarely ever good mojo.
Still, Sibe isn't exactly known for his detective work, so the guy (who doesn't appear to be the security honcho anyway, despite Sibe's claims) likely directly told him this. First rule of furry. For every idiotic action, there is an equal and opposite idiotic reaction. The man likes to stir trouble, but the con seems to be handling this in just about the stupidest way they can. Not over the banning, but over the tone.