Feeling the pressure of growing concerns over data privacy, most of the major Web search engine providers are stepping forward to better articulate how they handle the information they collect from their users. The latest to do this is Microsoft, which Monday outlined incremental improvements to its privacy principles for its Live Search and online advertising services.

Microsoft, which operates the number three search engine, joins search-engine leader Google, which made a similar policy-clarifying move earlier this year. Meanwhile, Yahoo, which operates the second-most popular search engine, has remained silent on the subject, seeing fit to stick with its current privacy policy.

Ask.com, a wholly-owned business of IAC that ranks fifth behind AOL Search, is the only search engine to address the privacy issue on multiple fronts. In addition to joining Microsoft on Monday in calling for the search industry to develop a common set of global privacy practices for data collection, use, and protection, Ask.com last week introduced its AskEraser tool that keeps Ask from storing information about its users' searches. Ask.com, wholly-owned business of IAC, plans to make AskEraser available on Ask.com in the U.S. and U.K. by the end of the year, and globally early next year.

Microsoft on Monday articulated in greater detail its privacy principles for Live Search as well as its online advertising services. The principles break down into five areas, the first of which promises Web users that Microsoft will continuously inform them of how the company gathers, secures, and shares search information. "We're not sharing anything that can be tied back to an individual," Brendon Lynch, Microsoft director of privacy strategy, told InformationWeek.

Microsoft, which later this year will begin offering advertising services to third-party Web sites that want to market to Microsoft search users, also will give those users the ability to opt-out of receiving these targeted ads. In addition, Microsoft will also make all Live Search query data -- including the IP address and cookie IDs -- anonymous after 18 months, unless the company receives user consent for a longer time period.

The company also will store Live Search service search terms separate from any personal information that could identify a Web surfer, such as name, e-mail address, or phone number data provided when a user signs up for a Hotmail account or some other service. Finally, Microsoft noted that when it begins offering advertising services on third-party Web sites, the company will join theNetwork Advertising Initiative, and follow the principles established by this cooperative group of Internet advertisers.