When Edgar Dworsky, a Massachusetts-based consumer advocate and founder of ConsumerWorld.org, shops through an unfamiliar website, he uses what's known as a virtual credit card number to avoid sharing his actual credit card number.
"With so many instances of online fraud and credit card numbers being stolen or hacked, either by [the merchant] or someone who might hack into their system," Dworsky says he doesn't want to take any chances that could compromise his credit card. He also uses a...