Since the beginning of forums there have been trolls and misinformation. There has always been the option to ignore, either by not replying or by blocking an offender from their view. However my experience has been that 1) people are almost universally incapable of ignoring trolls. 2) it is somehow almost impossible for people to stomach banning a troll knowing the troll is still posting.

The closest system that seems to work is for people to downvote whatever it is they dont like and for that to cause posts to have lower priority.