The whole YouTube (and Blogger) commenting system will shift to be powered exclusively by Google+. All comments must be tied to an account.

HELPING USERS…

For users, this change will likely be wonderful. First, it should banish some of the trolls spewing racism, sexism and homophobia. The anonymity of a one-off YouTube account created a safe haven for filth. People will still be able to create a pseudonymous G+ account and comment from that, but having to switch back and forth between that and their real accounts could be enough to silence some of the slurs. A more compassionate Internet, ahoy!

Relying on G+ will also give YouTube signals for ranking and sorting conversations in comments. Up top above random strangers, it can show comments from people you know, who are famous, that you’ve whitelisted, or who replied to one of your G+ posts. [Disclosure: Nundu Janakiram, a YouTube product manager on comments, is a friend and former roommate, but he’s had no influence or input on this article.]

…HELP GOOGLE

But for Google+ itself, becoming the backbone of YouTube comments makes it mandatory for a much wider audience, and could breathe life into what many consider a ghost town.

I’d point out, though, that the anonymity of the old YouTube commenting system wasn’t the only factor that created a “safe haven for filth.” YouTube’s comments are horrible because nobody in the organization is willing to assume the responsibility of overseeing them.

It’s the “broken window” metaphor applied to Internet comment sections. If nobody cares enough to fix the broken windows and prevent trolls and haters and assorted weirdos from taking over the neighborhood, more of them will show up until they do take over the neighborhood.

Comments on blogs and media sites don’t have to be awful. But almost inevitably, they will be awful unless someone steps in and stops trolls from dominating the discussion.

I’m not sure what Google is doing here is that altruistic, though. The possible troll-fighting effects are incidental; I think they’re much more interested in the greatly expanded access to users’ data this would give them.

But look, over there! It’s the NSA spying on your cell phone!

More: Google+ May Finally Matter Thanks to YouTube Comments