I've been trying to block a commenter who goes by the unlikely name of ReVonna LaSchatze; the commenter has personally insulted other commenters, and in a pretty vulgar way. Unfortunately, LaSchatze's posts come from different IP addresses, and don't use a fixed comment account that I can block. (To make things convenient for commenters, I don't require people to set up comment accounts, though I may have to change that.)
My solution to the problem has been to delete LaSchatze's comments, which has required me to delete or edit other comments that respond to LaSchatze. I'd rather not have to do that, because those responses come from valued commenters and took some time for them to post. So the request: Please don't respond to LaSchatze's comments.
By the way, just to remind people why I take the view I do about the need to maintain civility in comments, and the propriety of deleting commenters: Comment threads (unlike, say, all the videos on YouTube or generally even books in a bookstore) are a coherent conversation; for the conversation to be readable and pleasant to participate in, people have to maintain some minimum level of politeness. The analogy I give is a party that I host -- if people are rude enough to other guests, they won't be invited back, because that's how one keeps parties pleasant. I generally don't try to exclude people for their viewpoints, though I reserve the right to do that if the views are nasty enough. But I have and will exclude people who express their viewpoints in needlessly offensive ways, for instance by personally insulting fellow commenters.