Heres a news flash: YouTube uses Google Accounts. Which means all they are forcing users to do is link Google+ to their Google Account. Anonymous up down votes are kinda retarded to begin with. Part of the problem with the internet is people don't take ownership of their activities. Also, They do not need 50 ways to like content accross their properties. Social network federation is coming and you can certainly push you likes to multiple networks by using ifttt.com.