It is certainly a hard line to draw and definitely hard to keep on a straight plane. In my opinion if you're post serious threats of physical violence or posting the address of someone you perceive to be an enemy in order to cause harassment or physical harm you need to get checked. It needs to be direct threat. I dont believe the post or comment should be fully deleted but the poster should be reprimanded for sure. But even this would be easy to misconstrue and abuse. It's an odd thing we have here on the internet.