Are a lot of accounts replying at once, all around the same time?
Behaviour like this is sometimes called
What would tell them apart
One shape can start from nowhere organised at all — many separate people reaching the same thread on their own, all within a short window, with nothing connecting them but the thread itself. A different shape has a starting point somewhere else: a group that was directed or gathered elsewhere and arrived here together, which usually isn't something you can see just by reading the replies.
Why it might be none of these
Being visibly and publicly wrong about something draws a lot of replies, and that volume on its own is not evidence of anything organised. What's worth noticing is not the number of people but whether anyone is still actually engaging with the point, or whether the replies have stopped being about the point at all.
None of this covers stalking, doxxing, swatting or harassment campaigns. If any of that is closer to what you're facing, go straight to Red lines instead — the advice on this page was not written for it.