We thought about a "no unaccompanied minors" rule, but many kids of 16 and 17 were there and not posing any problems at all, and many younger kids who came in alone during the day (usually with parents attending something else in the same immediate area) were no problem. We don't want to discourage them from attending, nor do we want to give an "unfriendly to children" impression.
Clarity, of course we need to have behavior standards (which apply to adults as well as children) but the problem is enforcement. When an adult misbehaves, we can throw them out and assume they'll be okay. If we kick out a child (or, for that matter, whenever a child leaves our room alone late at night) we are concerned that he/she will get lost or harmed on the way back to the hotel. The majority of attendees were staying in hotels not connected to the convention center (meaning they had to go out onto downtown streets) and the connected hotel had a lot of non-con guests (hardly a closed environment) and a bar full of drunken revelers. True, it's not our legal responsibility to get those kids "home" safely...but we'd feel terrible if anything happened to a kid we'd kicked out. What would you suggest we do when we want a kid to leave?
Arduinna, I read a long article about an 8yo girl raped and murdered in a Nevada casino, and perhaps it was a different case than the one you're talking about, but this girl was abducted when she went to the restroom alone (killers had climbed in thru a window) and her dad let her go alone because there were no female adults in their party and he thought 8 was too old to go into the men's room. I think it was reasonable to expect that she was likely to be safe. In the situation as you describe it, however, while one can EXPECT that casino security and the relatively low odds of child murder will prevent such a thing from happening, that doesn't excuse the father from properly supervising his child. It's neither his nor the casino's fault this happened--it's a freak accident--but plenty of less serious things can happen to an 8yo left unattended in a video game room: harrassment by older kids or intoxicated adults, getting lost, falling down and getting hurt, theft of her money...none of these is life-shattering, but they'd be less devastating and less likely to happen at all with parents present.
I don't at all mean to suggest that parents of preteens need to keep them within sight at every single second in every type of public place. I just think it is foolish to think kids are more protected in an environment restricted to people who bought con badges, or in an indoor space, or among people who share one of your interests, than they are on the street. Maybe at a very small convention (like a few hundred, not 10,000) in a hotel with no other guests, you could trust "the village" to care for your child, but in a big con that's implausible.
MrBecca and I decided on the way home that this convention center was analogous to an airport: We might leave a preteen with strict orders to stay within one small area until we returned within no more than an hour, we might allow her to go alone to some specified location and return to us within no more than an hour, but we surely wouldn't go to sleep in our hotel room and allow her to wander the airport alone all night! We wouldn't be ABLE to sleep!
I guess that's the aspect of it that we understand least: These kids indicated that their parents were not playing games in some other room; they were asleep in the hotel, allowing the kids to come back whenever they got tired.
: Most parents don't let their PRETEENS stay out at the mall, in the park, etc., after parents have gone to bed, so they must be thinking this situation is different, but I don't see how.