And Facebook probably has a couple orders of magnitudes more, but you don't see anyone lining up to make a Facebook app for this. Besides, Wikipedia already ha

And Facebook probably has a couple orders of magnitudes more, but you don't see anyone lining up to make a Facebook app for this. Besides, Wikipedia already has user accounts. They even have a system for users with the appropriate permissions to approve revisions of a page -- no external crypto-nonsense needed.