“Yahoo! strongly believes that consumers want choice when customizing their online experience and they have also demonstrated a strong preference for advertising that is more personally relevant to them,” said Yahoo! privacy head and policy VP Anne Toth in a press release. “However, we understand that there are some users who prefer not to receive customized advertising and this opt-out will offer them even greater choice.”

Users already have the ability of opting out of “customized” ads on Yahoo.com and this new option will extend that choice to reflect websites outside the Yahoo! stable.

Yahoo! says it added the choice in response to an ongoing congressional inquiry into behavioral advertising – that is, tracking users around the internet in order to build an advertising profile from their activities – of which critics have raised privacy concerns.

Government regulators initially began their examination of targeted advertising once it became clear that ad networks were collecting staggering amounts of data on web surfers, in order to serve them relevant advertising. Some of this tracking included a record of partnered sites the user had visited, a fact that contributed to the U.S. government’s decision to step in.

An FTC summit into “ehavioral” advertising last November concluded with a dour warning to online advertisers: stop secretly tracking users, or else. Additional rules were suggested earlier this year; however, neither the FTC nor Congress has yet to enact any significant regulation on the matter.

Users who wish to opt out of Yahoo!’s targeted ad program can visit Yahoo.com’s privacy center, which Yahoo! says is available at a link on the bottom of almost every page on the site. Despite this availability, however, the company reports that only 75,000 visit its privacy policy page last month, suggesting that only a small portion of Yahoo.com visits will actually take the company up on its offer.

Yahoo’s letter to the House Energy and Commerce Committee indicates that the opt-out option is cookie-based, so users will need to use the opt-out page each time they use a different computer, or clear their browser’s cookies.