mildly annoying to plain bad. depends on how far the destruction from the mob reaches into real life.

ragging someone anonymous shitposter online can be solved by leaving the computer, but doxing someone and then getting them fired over non-violent acts such as speech is over the line. if someone is so despicable that it warrants prosecution leave the cancelling to the pros and get the police involved and then expose them all you like if it doesn't interfere with investigation.