The left has been allowed to get away with spewing lies misinformation and disinformation about conservatives for way too long now that someone is doing something about it. They’re shocked. 
Add to that, that they've been allowed to be violent with impunity, and had their violence whitewashed from the historical and statistical record.
All of the above make for a very dangerous bunch of people who think they can do and say anything without consequence.
And now the slightest of consequences are happening to them and they are losing their shit.