NessAndSonic: Still, courts tend to frown on clauses that are set up to escape liability. I learned that in my business law course. An example of this would be if your car gets vandalized in a parking garage. Even if the ticket says they can't be held liable, it doesn't matter. They were in charge of keeping your car safe while you parked there, and they failed their duty.
Likewise, there is another law in regards to minors entering into contracts. Those contracts can be worth absolutely nothing if a minor is involved. It was designed to be used as a defensive device to protect minors, not as a sword to steal. In short, they can't go to some fast food restaurant and use it to get free food.
The one variable I can't see that was mentioned in my business law class is that some contracts are still enforced if a minor lies about his or her age, but seeing as anyone under 18 is still a minor, I don't think a 12 claiming to be 13 years old would make much of a difference. If they claimed their age was closer to 20, then maybe it would be a different story.
Doesn't apply. That's why I caution people to make analogies between the internet and meat space. A business can inform people of the age limit, but they don't have any ability to actual enforce that provision.
Normally you would have a bouncer at the door and check IDs, the problem is that online you can't do that. You can ask for a license number, but nobody in their right mind would ever give one. And even if they did give one the site operator would have no way of actually determining if it were real and if it were for the individual showing it.
In short, no amount of due diligence on the part of the site operator is going to determine the real age of the individual agreeing to the ToS.
What's more, by lying about the age and pretending to be the eligible to agree they could very easily find the child to be trespassing on the site owners property. Yes, that's absurd, but it's not without precedence. Amazon used that line of reasoning to shut down a site that was indexing its deals.