Microsoft has agreed to meet the requirements of a European Union (EU) working party request that would see the software giant anonymize Internet search data after only six months. There's just one catch: It will do so only if its rivals--Google and Yahoo!--comply as well.

"We are prepared to meet the Article 29 Working Party's search anonymization guidelines, but believe it is imperative that all search companies adopt the same standard to truly protect people's privacy," Microsoft vice president John Vassallo said. "We've evaluated the multiple uses of search data and believe that we can, in time, move to a six month timeframe while retaining our strong method of anonymization."

Microsoft chief privacy strategist Peter Cullen says, however, that the software giant will not comply unless its competitors do so as well. "We don't believe it makes sense for us to make this change until our competitors also commit to meeting this higher standard with respect to both the method and timeframe for anonymization," he said.

Higher standards aside, Microsoft's desire to pull its competitors down with it seems aimed almost solely at putting market leader Google on the spot. "\[Google\] collects and retains much more search data than any other company and thereby has the greatest impact on the privacy of Internet search users," Cullen added. "Ultimately, the search engine that has access to the most data is able to improve the relevance of its search results, which provides more consumer value and gives the company a competitive advantage."

Sensitive information now collected and kept for varying lengths of time by search engines includes IP addresses, tracking cookies, and other data. Microsoft and Google currently retain this data for 18 months; Yahoo! does so for 13 months.

Whatever Microsoft does, there's no guarantee that the EU's working party request will become law: It's currently under discussion and Microsoft's proposed concession was part of a broader response to that request. The company owns just about 2 percent of the European Internet search market compared to Google's 80 percent.