It's much more of a threat to those who don't use cryptographic randomly generated passwords. And if you add PII to your accounts.

Because of this I use fastmail or Apple sign-in to make a new email for every online service I register for, and when it's a username I pull random words together from a dictionary. I also avoid using my real name as much as possible.

Identity theft and harassment. If you say anything politically that other people don't agree with then you could become a victim of violence.

well it might be embarrassing if someone found out you used facebook.

I guess I could envision a scenario where you're being investigated, and these leaks provide a roadmap of services to subpoena.

Maybe your phone number, relationship status or Facebook bio?

Posting like this will get you banned on HN, regardless of who or what you're replying to.

Could you please review https://news.ycombinator.com/newsguidelines.html and stick to the rules? We'd appreciate it.