Ad blockers are nothing new, and privacy settings on Internet Explorer and Firefox have long allowed users to opt out of some forms of advertising, but a beta version of Microsoft's new IE8 is raising some eyebrows in the interactive marketing community, according to an Associated Press report.

Users of the new IE8 who select the InPrivateBrowsing mode will be able to surf the web without sharing key data points with advertisers such as the previous sites they've visited. The privacy mode also allows users to view some websites without ads.

Firefox, which owns a significantly smaller segment of the browser market than Microsoft, launched an ad-blocking product last fall that stirred up a great deal of controversy, though it ultimately proved to be a non-issue despite widespread adoption by Firefox users. Yet, Microsoft's decision to enhance IE's ad blocking capabilities seems to be a rather curious choice given the company's insistence on becoming an advertising giant.

But according to JJ Richards, a general manager in Microsoft's advertising division, the decision will help to highlight the value exchange between free content and advertising that is vital to the future of the internet.

However, the new browser is treading on dangerous waters if it sees widespread adoption because it will block the ability of ad servers to calculate how many times an ad is viewed. According to Mike Zaneis, vice president of public policy for the Internet Advertising Bureau, the new browser could have drastic implications for the internet advertising marketplace. But Zaneis said he and the IAB would reserve judgment until Microsoft releases the final version of IE8.

There is no set date for the release of IE8, however the product is available for public beta testing.