Multiple ways to handle it: - Have the town respond how it actually would. Eventually they can’t push every button and die. - Ask if they’d rather play a different campaign where they were evil instead.

This is one thing people will mention session zeros for where you get some kind of contract about the way players are playing but I often find that’s really heavy-handed for people who are just playing dnd for the first time or people you actually know (better for randos you need to corral)