I once supported the idea of anonymous posting. I think I'm changing my mind.
On plenty of sites I've had to create an account once I had something to say, that I wanted to say badly enough to simply create and start keeping track of one more account. (And I never re-use passwords!) If I ever happen to have something to say on one of those sites, I've already got an account.
Also, creating an account doesn't necessarily make you suddenly lose your anonymity.
But I'm thinking the balance has shifted since the early days. Like when AOL poisoned Usenet by getting AOL onto Usenet, but that was before Slashdot. Or when the center of gravity on Slashdot shifted away from Linux users. But things change. Not all of it is trolling. Sometimes there are just different views. Bring up subjects like Java. Or Microsoft. Or tabs vs spaces. Vi vs Emacs. Is ST:TOS The Menagerie a single episode, or two episodes?
But if you have something to say about a topic like those, then sign in and say it. If you have something that is truly trolling (racist, sexist, offensive, etc), and not just something someone disagrees with, then creating an account is at least a minor barrier.
Being able to ignore a user is a good idea.