Officials from Xanga and Facebook did to respond to requests for comment.

A bill such as the one proposed in Connecticut "allows you to control the people who are willing to be controlled" but is unlikely to make much of a difference otherwise, said Pete Lindstrom, an analyst at Midvale, Utah-based Burton Group. "The notion of the predator is getting lost here. Are we trying to validate the kids who are underage trying to act overage, or the overage adults trying to act like they are underage?"

In most cases, the threat to minors visiting such sites comes not from other minors but from adults, he said. And those individuals are likely able to easily circumvent any age verification process a site might impose, he said. An attacker setting up a profile as his own son for instance would easily defeat age verification checks, he said.