I think that any increases you see in trolling has more to do with the state of online culture than it does with the ability to post anonymously. Reddit has an account-based upvote/downvote system, and trolling is still quite rampant there. It became such an issue that, in their desperation, they turned to highly overbearing moderators. And this resulted in an echochamber community that tolerates almost no deviations from the narrative set by respective moderators. I don't think we want that to happen to Slashdot, and a good step in avoiding that trap is by never making the first step toward it.