A "Social Justice Warrior" is what happens when you take liberalism to an extreme. When you take Conservatism to an extreme you end up with "Religious Patriotic Fanatics" who desperately want to be their own group's hero at the expense of other groups. While Social Justice Warriors desperately want to be someone else's hero at their own group's expense.
Both are extremes, unhealthy, and start out with good intentions. Social Justice Warriors often times fantasize about making bullying, name calling, and stereotyping illegal. They can be found in high concentration at places like Reddit, Vice, & Gawker Media sites constantly talking about race/gender/class while ignoring statistics on race/gender/class. They demand that you are politically correct in everything you say. Their favorite insults are "you're racist" and "you're sexist". Basically "the thought police".
Example; When Paul Graham of Y-Combinator mentioned how strong foreign accents can hinder a founder's ability to communicate with his team (which is common sense) he was attacked by silicon valley news outlets for being anti-immigrant, possibly racist, and xenophobic. When he later gave his opinion on why there's so few women in tech he was again attacked and called sexist. This is the problem with Social Justice Warriors, they are warriors, warriors are willing to go to extremes to achieve hero status.
In moderation social justice isn't bad. Religion or patriotism isn't bad either. Neither is conservatism or liberalism. But when taken to an extreme these ideologies end up becoming illogical, irrational, and causing damage to a society's expressive or civil freedoms.
