Did anyone sign up to that with their real name or email?

I'm certain many people signed up using established internet identities which can then be linked to real world identities through social engineering techniques.

Unless you had a unique email just for that service, you could just cross link it with another leak that contains your name.

Sure it’s possible to have perfect op sec but almost no one does in reality.

I did. I couldn't care less if people know I write fanfiction. I talk about it IRL with people, completely without shame. firstnamelastname@gmail.com

I am certain that many people will have signed up with an email address that contains their real name. If this leaks I’ve gotta imagine that someone with a particularly dark/evil sense of honour makes a tool where you enter an email address and are shown an AO3 presence.

If you put a phone number into Grindr's "forgot password" feature it tells you whether there's an account with that phone number or not.