We get lots of trolls when new movies are released, and they turn the various threads into a major mess.
We had to limit new registrations one of the times.
The current Last Jedi mayhem seems to have subsided, but thinking proactively, here are some options to consider:
a) always disable new registrations for the first month a new movie is out
b) put new users through more rigorous screening (not currently possible?)
c) make it easier to block new users until a moderator steps in