Wack-a-mole. That’s what it’s usually like fighting trolls, bullies, and spammers in anonymous communities. Ban them and they just start new accounts. That’s why the fact that Facebook knows who you really are could be the key to its upcoming anonymous app.

You could stay anonymous to other users, but Facebook login on the backend could track the jerks and keep them out. Powered by its anti-thesis, Facebook could unlock the potential of anonymity to let people open up and be vulnerable.

Facebook’s original value was that it knew who you were. Years of pseudo-anonymity on MySpace fostered openness but also a total distrust that anyone was who they said. Demanding people use their real names and verifying them by their college email ushered in an era of authentic identity.

With it came more civil discussion. People could be held accountable for their comments and actions. When your reputation is on the line, people typically exhibit less bullying, trolling, spamming, sexism, racism, homophobia, violent threats, and other disruptive behavior. That permits rational conversation, even about polarizing subjects.

Facebook eventually built an embeddable commenting widget to bring authentic identity to the comment reels of blogs and other websites. It worked. At TechCrunch we saw a marked decrease in dirtbaggery when we switched to Facebook comments.

But what authentic identity curtails is the expression of polite but controversial and unpopular opinions that people might not want connected to their name. It can also discourage participation in threads about sensitive or deeply personal topics like health, sexuality, relationships, and religion. That’s unfortunate because these are exactly the types of conversations susceptible to trolling and hate.

So anonymity enables vulnerable sharing but also disruption of this sharing, while authentic identity safeguards but also encroaches on open-hearted discourse.