Well, it's not really a pain in the ass. I'm assuming that this is either intentional or they coded it badly. I guess that now it works like this: when new tease is created check if sender is blacklisted, if yes then hide the tease. All they have to do to make it retroactive is perform the check while fetching teases from database to display them to user. Not really that hard, that's why I think it's probably intentional.