I was just wondering if this is possible for the Mods. The idea here is that once a thread starts heading off the rails, maybe the Mods could block certain posters who are taking it there from just that particular thread. It could be a last ditch effort to preserve a thread before locking it. I think we've all seen that in most popular threads that get locked, it's just a small handful of posters that are causing a problem. Obviously, if people feel so strongly that they start creating new log-ins to jump back into the fray, the thread could be locked (or, alternatively, the ban hammer could be wielded).
A more controversial alternative would be to allow users to ban people from threads they create (either at the outset or after the fact).
