Social Justice Bullies 

People who do not realize that people make ignorant mistakes. Mostly from what I've seen Tumblr plays a huge part in this. Basically, SJBs are people that see someone has said something wrong or anti-semitic and they get on social media, call them out, (which is fine) but then they take it to another level and pretend to be for social justice, but it boils down to them just disliking the individual so they bully that person to the point of no return without realizing that people do make ignorant and honest mistakes. (Even if the inciter has educated their self and perhaps presented a public apology that is sincere to the core.)

"I'm definitely down for social justice, but these Social Justice Bullies are a real problem."
"She is honestly sorry, but the Social Justice Bullies do not care for her resolution because they get off on calling people out via Tumblr without trying to educate them."

Social Justice Bullies by Le17 October 4, 2016