After many years of being the definitive net software browser, Microsoft’s Internet Explorer has received a new and flashy, no doubt Gates-approved update.

Unfortunately for advertisers, this includes a privacy mode that can block access to users’ browsing habits from third-party sites, stopping unwanted ads.

The InPrivate setting, available on Explorer 8, lets users see in advance what content is being sent through from third parties when visiting a site.

It can then block the content, which may include advertising, movement tracking software and anything else that may interrupt someone’s daily porn surf.

Funnily enough, it has already been dubbed ‘porn mode’ because web cookies and the user’s browsing history are deleted when the tab is closed (no more manual deleting!).

InPrivate effectively works against certain ad models, including the one used by Google‘s newly-acquired DoubleClick business, which delivers targeted advertising to users based on their browsing habits. For marketers salivating at the prospects of performance-based advertising networks, the move is potentially disastrous.

Analysts have suggested that if the attention around net privacy gains momentum, more users will hit the privacy button – a major threat to click-through advertising technology.

Other browsers already have a similar privacy option to InPrivate but Microsoft has given the setting a much more prominent position in its new version.

If InPrivate does catch on, a new perspective will be needed by companies centred on digital services.