The most obvious legal claim at the moment is that Tea was negligent about its security.

I suspect that's going to be more of a problem for Tea than hypothetical individual defamation cases.

Although having said that, how can you sue someone for defamation if you never find out you're being defamed?

Any woman can say "Don't date [name], he's a bad person" and the victim will never know.

Unless he asks a female friend for a social credit check, all [name] will see is a shrinking pool of opportunities.

If it's an opinion or a statement of a fact it isn't defamation.

"He's a bad person and you shouldn't date him" is an opinion you can legally express anywhere as much as you want.