@pluralistic Reddit “circlejerk” communities are often adversarial to the community they affix. For example, there’s r/fuckcars, which is anti-car, and r/fuckcarscirclejerk, which just mocks r/fuckcars posts all day as ridiculous.
This wasn’t always the case in other online communities; there, a topic “circlejerk” referred to an undying thread for fans of a topic to discuss it ceaselessly. But for some reason, on Reddit, semantic drift has flipped the meaning of the affix.