Web bugs are concealed software that collect information about surfers.
They are often hidden in banner ads. A recent study of 1 million Web sites by the Internet tracking company Cyveillance concluded that there are over five times as many of these spies as in 1998. Overall, the pests showed up on 3.9 percent of all sites, compared to 0.7 sites three years ago. Defenders of Web bugs say they don't collect names, physical addresses, phone numbers, credit card number, or any information that would identify you personally. They insist they use bugs to watch consumer trends, gather statistical data and even scan for copyright violations.