A good question. Apart from credit card verification methods (I'm sure that would go down like a lead balloon o n Facebook) what other methods are available to organisations such as Facebook (they claim a minimum age of 13 for users of their service).<p>Is asking for a date of birth really fulfilling Facebook's quota of responsibility?<p>What would something like this cost the big social networks, not just in monetary terms, but ease of use and user opinion?
For all its faults, the recently-proposed NSTIC should solve this problem. Ultimately, any solution is going to require expensive in-person enrollment.