Speaking from literary experience and second-hand report from friends who've been targetted by coteries who make the Heathers look benign (but don't even realise that they're not the heroines of the hour in so doing, which is the pernicious part).

I thought you were one of them, but maybe that was yet another online teenage acquaintance who found herself as the inadvertent target for speaking up in support of someone the queen bees wanted silenced and shunned...