I have had an eBay username and password.
While looking at things on eBay a bit ago and I was prompted to enter a password. I entered the one that I have used. Guess what? It came back with a suggested username which is what it has been. as if I got a new account but didn't (or did) (or ?) I use three browsers, multiple emails, mobile phone, PC and a MacBook Pro.
Suggested what my username already was by entering a password.