Yahoo and Microsoft have proposed a partnership in search and advertising, prompting legislators to review privacy issues in behaviorally targeted marketing practices that track users’ activity online. Federal legislation has been proposed to allow users to actively “opt in” to programs that track their browsing. Currently, users to opt-out of behavioral tracking and few people bother to do so.

Yahoo reported that out of 140 million U.S. visitors to its sites in July 2008, “approximately 75,000” visited its opt-out page. Microsoft reported that out of 130 million U.S. visitors to its sites in August 2008, only approximately 1,800 opted out. eMarketer estimates that spending on behaviorally targeted advertising in the U.S. will quadruple to $4.4 billion by 2012.

Source: http://www.marketwatch.com/story/planned-privacy-law-may-hamper-online-ad-industry-2009-09-01