Microsoft launches 'porn mode' browser that lets you surf the web without leaving a trace

Microsoft has launched a new internet browser that will let people surf the web without leaving a trace of the sites they have visited.

Nicknamed 'porn mode', the InPrivate feature on the firm's newest version of Internet Explorer hides the browsing history from any other people who are using the same computer.

The setting will come as a blow to internet rival Google which relies heavily on users' browsing histories to deliver targeted advertising.

Firms like Google have caused an outcry over the way they gather information about people's surfing habits and then use the information to decide which adverts to show.

Google currently only makes 10 per cent of its money from display advertising but is hoping to increase this percentage in the near future.

The program also covers other footprints, including temporary Internet files and cookies, the small data files that websites put on visitors' computers to track their activities.

Both Internet Explorer 7, Microsoft's current browser, and Mozilla's recently released Firefox 3, already allow users to block cookies. But they can't turn off that collection entirely.

Another feature, known as InPrivateBlocking, stops certain types of ads being seen, which will come as a blow to those smaller companies that rely on this sort of advertising to make money.

A screenshot of the new browser which allows users to keep their browsing history secret

InPrivateBlocking isn't purely an ad-blocker by design, but publishers are still worried, said Mike Zaneis, vice president of public policy for the Internet Advertising Bureau, which represents web publishers.

If InPrivateBlocking were widely adopted by IE8 users, small sites that rely almost exclusively on outside companies to serve ads couldn't survive, he said.

If IE8 blocks programs that track how many times an ad is seen - a calculation that helps determine payments to advertisers and publishers - that could also bring down the web advertising marketplace, Zaneis warned.

'We'll wait and see what the marketplace looks like,' he said. 'I think (Microsoft) realises that it's a beta version, and it's sure to change before it's finalised.'

Users surfing with InPrivateBlocking turned on can review a list of which companies are trying to display or collect data.

Users can also click a link to read more and decide case by case whether to permit certain ones to go ahead.