I believe it can be shown that PayPal is failing to render an advertised service(Credit card funding) in good faith by manipulating default user behaviors(through software) towards a rival and exclusive service(bank funding) in such a way that is *purposefully* ambiguous of informed consent.
A furtive, self-interested* policy which works to obfuscate(or deny outright) alternate funding options - by decreasing their visibility through strategic placement - represents potential user liability in the form of funding errors with implications not only for lost time, conveneience, and business, but also monetary fees incurred through Non-sufficient funds.
* PayPal deters credit card funding in an effort to limit their own chargeback liability and credit card processing fees.
Thus, any such design must be deemed grossly negligent.
Further, as - unlike many PayPal customer grievences - this behavior is *not* sanctioned in the user contract, it poses not only ethical problems, but shows a willful deception on behalf of PayPal that lends itself to interpretations of fraud and legal remedy.
I hereby state that Paypal has abused my trust(and have virtual and/or physic evidence to support this allegation) by manipulating and/or denying my informed consent of funding options, in such a way as to incur personal and/or professional liability.
PayPal software deceptively manipulates hapless consumers into using a bank-account funding source, often without their consent, and frequently against their better interests.