[user5994461]

To answer you, the account was associated with my real email but had no password. Saw after deleting the account because it sent a deletion confirmation to my real personal email (that it should never have had in the first place).

To answer the parent post, OAuth doesn't automatically associate accounts. The first time you login (signup) to something with linkedin/google/facebook it gives you a popup warning that you're about to authenticate and share data with a third party service, please confirm.

If you see that popup on login, you don't have an account, don't proceed.

[prophesi]

Thanks, I didn't see that popup upon logging in, and swiftly deleted the account.