I think it's easy to make Twitter the bad guy, censor and you get called out for it, allow free speech and they become responsible for people's actions.

The polarity increase between "us" and "them" and especially the political animosity between parties is the catalyst for this kind of radicalism. It no longer feels like American first, politics second.

Are we able to detect sarcasm using artificial intelligence yet? Because until that's possible, the credibility of a threat is going to be the job of law enforcement and not Twitter.