Intel's decision has raised an issue that straddles the fine line between e-commerce convenience and potential loss of privacy for buyers. Detractors accuse Intel of compromising user privacy for potential marketing gains, because the ID would allow users to be tracked on the Internet and profiled. Cookies - software picked up and stored on the hard drive of site visitors - is used for similar tracking purposes, but can be deleted or refused by the user. Intel has promised not to collect a database of Pentium III customer names and serial numbers, but there is no way to prevent others from doing so. The idea of tracking Internet users in a way that could recognise the identity of each individual is not new. A report last year by News.com said Microsoft proposed to develop a digital-signature feature that would confirm whether an item of communication was tampered with after it was 'signed' by its author. This would lead Net users to 'sign' nearly all digital documents, Web content and e-mails, making their identity easier to track. This feature was pushed aggressively by Microsoft chairman Bill Gates after a meeting with mainland officials, said News.com. However, it has been suggested that enabling mainland authorities - which control the country's Internet - to track Web content authors would help it find dissidents who had posted electronic newsletters. Intel said software companies asked it to build an ID feature into chips. Intel was developing software patches with which users could switch the feature on and off, a company spokesman said.