What is the origin of the phrase "social justice warrior"?
RationalWiki says that the phrase "social justice" (without warrior) originated in the 1840s.
Searching twitter for top tweets about "social justice warrior" got hits as early as August 2009. One tweet lead me to the ACLU blog post In Memory of a Social Justice Warrior: LGBT Rights Champion Carolyn Wagner from January 2011.
When and how did it become a popular phrase, possibly with capital letters ("Social Justice Warrior")? Also, was it coined and/or popularized by people who support social justice, their opponents, or a third party?