When I was in college in the mid 2010s, Gamergate had already cast a distinctly political and critical tone over everything. It's what led to the Hallowen event It's Okay To Be White (IOTBW) and He Will Not Divide Us (HWNDU) trolling. Aside from murders, that was the last distinctly Anon Babble thing to happen IRL to my knowledge.
I wasn't posting with the expectation of such things occurring anyway. In fact, the retort "not your personal army" was often flung at anyone trying to call for a raid of some sort, which is to brigading was discouraged.
But again, you didn't need any of that, because 10 years ago many boards were still treated like serious hobbyist and enthusiast boards, including this one. There were knowledgeable and passionate people who shared a ton of insights and original content from which you could learn way more than you ever imagined possible.
But by the late 2010s when zoomers were coming in en masse, those communities started dying because zoomers were simultaneously ignorant and deinvested and shit-tasted, frankly. You'd just see endless threads of shitposting and cluelessness while anything of worth got ignored. And that trend continues through the present day.
So depending on what you consider cool, it could have happened anywhere within the early 2010s.