I think that you're misunderstanding your parent, who is not, to my reading, saying that people will show up at your work and beat you up or yell at you, but rather that they will campaign to get you fired.

For example, Scott Alexander of Slate Star Codex mentioned in a recent post that people had called his employer and tried to get him fired because of the comments of people on his blog and the subreddit associated with it. (And he blogs pseudonymously, for whatever it's worth).