I would be willing to bet that you do not report every threatening post on your own forum. You intelligently judge whether or not there is a credible threat.
If someone posted that they want to be a a famous school shooter, I would indeed report it. If someone posted a serious death threat, I would report it. When it's two posters who don't even know each other going back and forth and insinuating they want to beat each other up, I take it for what it is - childish cyberblather.
In fact I have alerted the police when we had a crazy on here that I thought was a serious threat. I have also alerted SMCSO when I saw death threats being made on a local person's FB page.
Not that the cops can do anything about it anyway because they are pretty much prevented from investigating internet threats. The crazy has to actually kill someone first before they can do anything about it. The most the victim can do is get a restraining order, and umpteen women who were killed by their ex person who had an order against him pretty much prove that it isn't a deterrent.
If you see crazy on social media, you can report it until your fingers fall off and nothing will be done. They won't even delete the post in many cases.
So now the mantra is "if you see something, say something," which is all well and good....but then what?
Then nothing, that's what.