In 2012 till Junr 2014 one guy (pretty sure it was the same) always mentioned that rapeing joker would force him to be crimeless though no gordon yet. Peak was around 2013.
Reason for this probably the killing joke rerelease.
From June 2014 till March 2016 he posted regulary using the animated gordon for the first time though it was always in "why doesn't he rape?" Format.
The picture was also not the current one, it was gordon looking at the viewer with bullock behind him.
March 29 he posted Gordon wielding a gun and stating "if you don't rape him....".
This one hit bump limit.
I believe this is tje origin