xenolith, you may be right, in the long run, that a debit card and a credit card have equivalent fraud protection. However, in the SHORT run, ie a few weeks, there is a HUGE difference. And it is exactly as I stated it initially.
If someone scams your credit card, you may not realize it until you get a bill. Despite this, you still have ALL of your money. If you protest the charges successfully, you never have to pay and you keep your money. On the other hand...
If someone scams your debit card, the money comes straight out of your checking account. It is gone, gone, GONE. You don't find out when you get a bill, you find out when you start getting bounced check notices in the mail. You get hit by your bank with NSF charges. You get hit by with bounced check fees by the businesses you wrote checks to. You could POSSIBLY even get arrested. When you finally realize what has happened, you file a protest. Then, at some time, maybe weeks in the future, you back MAY give you back your money. And you still have to hassle with the fees and the bad checks and everything.
There is a WORLD of difference.
And, for that matter, as I recall, what PayPay wants from you is NOT a debit card number, but rather an actual check so that they can establish direct EFT draft transfers. This bypasses whatever protection the fake-VISA cards have or claim to have. And leave you MORE at the mercy of your banker. Assuming that your banker has any mecry for you to be at, which is unlikely.
NEVER, NEVER, NEVER authorize any on-line merchant to do direct checking account drafts. If you do, and something happens, you are SCREWED, SCREWED, SCREWED!