Watch out for :fedposting: obviously.
My spouse works in medicine. A lib boomer doctor coworker of hers has been a family friend for decades. He and I would debate sometimes on Facebook. It never got too rowdy until about six months ago, maybe earlier. I can't remember what it was about, but I was probably going on and on about Biden sux, death to amerikkka, etc., etc. I think almost all of my Facebook friends, the vast majority of whom I had not spoken with in at least ten years, had muted me by then. But this guy came onto my wall and was just much more tenacious than usual. It sucked because I've known him forever, I genuinely like him, and I was literally in love with one of his kids for many years in school. The debate went on for several days. We never called each other names or insulted each other, but it was still pretty intense. My spouse's coworkers commented about it to her at work. I don't remember what they said, but I want to believe it was something like: "your unemployed commie husband is repeatedly bodying [respected doctor] on Facebook." She asked me to get off Facebook because she said it was endangering her job. I agreed to go, and actually I'm very happy that I did, since Facebook is a cesspit and echo chamber. Later we found out that the doctor was in the hospital with covid, and some nurses had seen him angrily typing a lot on his phone when we were debating. He recovered from covid AFAIK, while I have been off Facebook since then.
Not really but I don't get into fights online.
I've definitely posted concise demonstrations or evidence that contradicts reactionary narratives on Twitter in the past though, including one in which a clearly drunk Tory MP responded about a dozen times over five hours in which I didn't reply once, winding themselves up enough that they eventually posted a tweet that their staff made them pull and apologise for the next day for the 'insulting and foul names' it used. It wasn't a major scandal or anything, but it was nice to have inspired a little humiliation. I won't share the specifics as it was under my real name though.
I've had one close encounter, where a client who used to comment that I always tweeted about 'really interesting news' (meaning not what's on the front page of international section of your standard broadsheet) had a sudden revelation that there was an underlying theme (I wasn't hiding it) of left-wing movements, organised labour, China, Vietnam, South American anti-fascist action etc etc and asked me at our next work lunch whether I "was a communist or something." He definitely wasn't a raging chud, probably a centre-right British liberal, but I wasn't sure at all how it would go. But I just said, "no or something. I'm just a communist." There was a moment of silence where it looked like his brain had broken and I wondered where it was going, but then he just seemed really fascinated by the novelty of it; the idea of doing business with a business person at a business lunch who also happened to be a communist.
I've definitely known people, in particular a freelance web designer and graphic artist, who posted some pretty mild context and criticism of the early Ukraine war narrative and lost a decent amount of work from it after a chud client started reaching out to a lot of other clients sending emails that totally misconstrued what he'd said and claimed he was a pro-Putin racist who was cheering on the war. Most ignored it but they definitely lost a few projects and it was a tough time for them.