>>516579322
2011 was the start.
Occupy Wallstreet was the topical event, but the true catalytic event was the bifurcation of internet counter culture.
Up until that point reddit was a sort of sister site to 4chan.
On /pol/ or /new/ you could find intelligent debate between every flavor of political extremist from fascists to communists to monarchists, to anarchists.
The introduction of the progressive stack though created a new racial hierarchy based on arbitrary perceptions of oppression.
Suddenly what people were (gay, straight, white, black) became more important than what they said.
The leftists supported this, but the rightists rejected it.
The split led to the exodus of the leftists to lefty/pol/ and the culture war ensued from there.
Remember that back in those days we were mostly hacktivists.
"Cancellation" was just a weapon used in the culture war and before it became mainstream it was just called brigading.
A common hacktivist tactic back in the day was to uncover dirt on people and leak it to the media.
Gamergate happened when some neutral hacktivist gamers tried to apply this tactic to some corrupt game journalists.
This was when it was revealed that the media is leftist aligned.