This deduction makes no sense because PayPal isn't publishing those things. Their checkout-with-PayPal service is not much more than a link on a website, in most cases.
But even if PayPal were trying to use that service to copyright the material on the originating website, it wouldn't fly in court.
If PayPal's legal boilerplate really bothers you, you'll have trouble browsing top few thousand websites at all (most popular sites have broad and vague agreements like this).
On a related note, PayPal is pretty easy to avoid these days, if one is so inclined. The behavior of Facebook and Google are much more worrisome, as they're totally impossible to avoid.