The Sandy Hook conspiracy theories are a good example of a modern day witch hunt.

The vast majority of it is being driven by black propaganda from agents with nefarious goals at its source, but a lot of people pushing the witch hunt are irrational, paranoid, and naive people who have formed into a semi-cohesive mass attack. Many innocent people have been harmed by it, and innocent people's live have been threatened over it.

black propaganda AKA disinformation campaign:
[link to en.wikipedia.org]