Social Justice Warriors are the Western equivalent of Saudi religious police or Chinese censors. They are usually white and in their early to mid 30s and are often struggling or feel disadvantaged in some way in their personal lives. They act as unpaid enforcers for the Democrat Party on social media, usually by picking targets of some public renown, and then calling for “action” against that target.
Such action usually consists of hundreds or thousands of angry tweets demanding public apologies and attempt to shame the target at a minimum. Other actions may include “doxxing” a target – releasing his or her real name on the internet in the hopes of inciting physical violence – and calling the target’s job, friends, and family and making false claims about the target (usually including false claims of sexual assault/violence) in an attempt to destroy the target’s personal life.
Because Social Justice Warriors are leftists, media outlets looking for stories will often follow their lead in doxxing and harassing helpless victims. Matt Taylor is a typical example of the media following the lead of SJWs: http://www.telegraph.co.uk/news/science/space/11231320/Rosetta-mission-scientist-Dr-Matt-Taylor-cries-during-apology-over-offensive-shirt.html
The ringleaders of such social media mobs gain social credibility among their fellow SJWs if they successfully lead a ‘takedown’ of a target. In some cases, the most successful SJWs can leverage this into to Patreon donations and favorable media coverage and TV appearances.