Does the ignore button is useless since many posters reply or just talk about the trolls?. Many people do not like to be told  to put a troll on ignore. So I do not see the point to announce publicly that you put someone on ignore, just do it. If all the people who put a person on ignore would announce it, this group would be a lot worse. The only people recalling us a troll is active, it is when you post about him so it gives him the importance he needs. You are feeding him.