But figuring out whether a comment contains suicide encouragement, gore or sexually explicit content is a lot easier than figuring out if something's a spoiler. You're asking case to have an encyclopedic knowledge of every single fandom that appears on FS, including its chronology. It also assumes there's a general consensus on the statue of limitations for spoilers, and what the penalty should be, and how to enforce banning when it comes to people without signed accounts.

I don't disagree that it'd be nice to do something about trolls who post spoilers, but I'm not seeing where it's feasible to monitor the community to stop them beyond what case is doing now: acting as quickly as he can if/when alerted by the users.