I have a relentless human spammer that is extraordinarily difficult to keep away. Spam filters are unhelpful as he does not use a set of frequently used words. Rather, his insults are more "subtle" to be captured by any regext. Each time I block him, he comes back with a new username but soon the new user reveals his spammy nature. So I need to go through the list of comment to finds the one by him and delete them one by one. On the other hand, I don't want to disable comments auto-approval just because of one bad apple.
It is painful especially when you need to do it a couple of times a day! so I wish there was an easier way to sort and then delete comments of a particular user, and not involved direct querying the database?