If you use PayPal, you may have noticed its new-ish feature: Bill Me Later. Proceed carefully. Check the default payment method.
Somehow I (and others) have unwittingly and unintentionally used Bill Me Later when making a payment through PayPal, maybe with Bill Me Later set as the default.
The sequence went all the way through the billing and payment process without alerting me that I was using Bill Me Later. Nor did I know I had set up a Bill Me Later account--it was done very smoothly, all the while looking as if I were still in PayPal.
Not only that, Bill Me Later somehow acquired all my personal information from PayPal! Luckily I was able to make the Bill Me Later payment without a further hitch and close out the account I never opened.
Save yourself some trouble and look carefully before you leave the initial PayPal page--make sure you're paying with PayPal. It's not exactly a scam--it's a trompe l'oeil.