PayPal Virtual Debit Card FAQS - I can almost take credit for this. I had this idea at least a year ago. Granted, it wasn’t via PayPal but for any standard credit card. If I was atop a company in the industry I would have made it happen. What is it? To insure that credit card number theft and subsequent purchases are not possible PayPal will generate a one-time-use MasterCard number for use with your online purchases. This means when you buy something at online site a shady employee can’t reuse your credit card number to make another purchase elseware. At least that’s how I thought it up and interpret the FAQ. I may even use this, once it’s out of BETA.