usually yes, but that depends on what and where you are purchasing. or are you just signing up? PayPal is a legitimate company. Paranoia is not warranted when making a purchase, just enter your credit card # into your paypal account and if anything goes wrong you just call your credit card company and they will give you your money back. No one sees your credit card number it's all encoded.
at 8:27 AM on Mar. 19, 2009