Even if we blithely assume that this means there are more trolls today than a year ago, it seems unlikely that a rule restricting them to trolling only in SOPW would do anything to change that. I can see the OP's suggestion, if implemented, maybe doing a bit to cut down on posts to the wrong section (...which itself assumes that most AnonyMonk posts are the sort of thing that belongs in SOPW), but that's about it. The content of the posts would still be exactly the same.