[kyochan]

"Do we have a right to be anonymous online?"

No. Not a right, especially when performing constitutionally-protected actions. I don't believe people should be required to identify themselves online, but I do believe that people who post anonymously should expect to be exposed eventually.

A better question would be whether legal channels should be used in the exposure of an anonymous person.

I believe so only if all other option are exhausted.

"Do the pros outweigh the cons?"

Yes, but only in place where free speech is not protected by the state.