I recently was emailed from HaveIBeenPwned.com (which I am signed up on) about the ShareThis website/tool (not signed up on).
I have no memory of signing up for that service.
When I go to recover the account (I might as well close/change password), I get this:
The two facts seem mutually exclusive:
Either I had an account and it was pwned, or I didn't have an account (and thus HIBP is in error)?
How do I find out the true situation, and what is the most secure course of action?