hiero writes "From an article in the Star Tribune: 'Federal authorities said Tuesday they thwarted an extortion plot against Best Buy Co. Inc. by a man who sent the company an e-mail threatening to expose what he claimed were weaknesses in the retailer's computer system unless he was paid $2.5 million.' What's really interesting to me, though, is this paragraph further on in the article: 'The federal search warrant was obtained the morning of Oct. 24 and allowed the FBI, with Best Buy's cooperation, to use an Internet device known as an Internet Protocol Address Verifier. It contained a program that automatically sent back a response to Best Buy after the company sent a message to the e-mail address. The response allowed investigators to identify Ray as the sender of the e-mail threats, according to the government.' Internet Protocol Address Verifier? Is this Carnivore in action?"