They've always been out there. They can find each other and assemble far more effectively now though. Youtube is now the only place where algorithms can get me. My Facebook is defunct, my Twitter is deleted, I don't have any other social media unless you count Whatsapp.
And after initial months of aggressively blocking anything with even a whiff of culture war off it a few years back, I can now proudly say the only recommended vids I get are Warhammer, NFL, Attitude era wrestling and clips of Moneyball and the Matrix.