I mean think about it...you're gonna let some nerd glued to a screen & keyboard hurt your feelings?  People take knucklehead internet bantering that seriously?  

THERE you are, peacefully reading an article or watching a video on the Internet. You finish, find it thought-provoking, and scroll down to the comments section to see what other people thought. And there, lurking among dozens of well-intentioned opinions, is a troll.

"How much longer is the media going to milk this beyond tired story?" "These guys are frauds." "Your idiocy is disturbing." "We're just trying to make the world a better place one brainwashed, ignorant idiot at a time." These are the trollish comments, all from anonymous sources, that you could have found after reading a CNN article on the rescue of the Chilean miners.

the opening paragraphs tells you all you need to know about this person.
they are one of the ones who can not abide anything happening anywhere in the world or most especially on "their" internet that they do not approve of.

it simply should not be allowed.

You can already see this with sites that have you link to existing identity networks: e.g. you log in with your Google account, your Wordpress account etc, thus linking your existing blogs and information to your posts. No doubt Facebook would like to add its name to that list.