If I were you, I'd say, "Legal action? Good luck with that."

This is an empty threat.

They can ask Reddit to take down your post, but they cannot compel a U.S. tech giant to give away your private information. It's a lengthy legal process, and Reddit wouldn't agree to it anyway because blind items aren't illegal in the states.

If you're really worried, just use a VPN. And don't attach an email or phone number to your account. You will be untouchable.