I was commenting on the causal relationship. The fact that vigilante social pressure is easier today is technically true, but not really addressing my point about the fact that people wanted (and did) do this. Your example is a guess. I promise you, in 1990 if I wanted to ruin someone's life, I could have (go check out the movie Fear).
The Salem Witch Trials were cancel culture. Jim Crow lynch mobs were cancel culture. The Red Scare was cancel culture. Same idea, new execution.
(Edited for spelling error)
I don't think anyone had tools like this at their disposal in the 1990s. You could call up someone's employer and lie about an employee saying something bad about immigrants at a birthday party and they'd probably just hang up on you or threaten to call the police for harassment.