Microsoft is the first of the major search engines to agree to the European Union’s demand that data retention be cut to six months. The company will now completely delete IP addresses after six months. Here’s what Microsoft said on the Bing community blog about the move:

Today we sent a letter to the Article 29 Working Party notifying them of our intention to make a change to Bing’s data retention policy.

Specifically, we are reducing the amount of time we store IP addresses from searchers to 6 months.  Currently we keep that information for 18 months before we delete it.  Generally, when Bing receives search data we do a few things: first, we take steps to separate your account information (such as email or phone number) from other information (what the query was, for example). Then, after 18 months we take the additional step of deleting the IP address and any other cross session IDs associated with the query. Under the new policy, we will continue to take all the steps we applied previously – but now we will remove the IP address completely at 6 months, instead of 18 months.

Google and Yahoo have yet to agree to this, but Microsoft’s move puts pressure on them to do so. Google has argued in the past that it needs to store user date to improve the quality of search:

Back in March 2007, Google became the first leading search engine to announce a policy to anonymize our search server logs in the interests of privacy. And many others in the industry quickly followed our lead. Although that was good for privacy, it was a difficult decision because the routine server log data we collect has always been a critical ingredient of innovation. We have published a series of blog posts explaining how we use logs data for the benefit of our users: to make improvements to search quality, improve security, fight fraud and reduce spam.

Currently Google “anonymizes” IP addresses on its server logs after nine months. Again, what Microsoft is agreeing to do is not just make anonymous but completely delete IP addresses after six months.

Google will likely have to match Microsoft’s position and will have difficulty continuing to argue that IP data retention for more than six months is necessary for any purpose. Yahoo may, upon implementation of the Microsoft-Yahoo Search deal, automatically be opted in to this via Microsoft’s compliance.

Here are previous posts on this subject:

• Google Halves Data Retention Time Against Backdrop Of EU Pressure, US Regulatory Scrutiny
• European Groups Says Search Engines Must Delete Search Data Within Six Months
• Google, Yahoo, Microsoft, & Other Search Engines Must Comply With EU Privacy Rules
• Microsoft To Anonymize Log Data; Calls For Industry Standards Along With Ask.com
• EU Group May Serve Google With Letter Over Data Retention Policies
• European Union Questions Google’s Data Retention Policy

Related Topics: Google: Critics | Google: General | Google: Legal | Google: Outside US | Microsoft: Bing | Microsoft: General | Microsoft: Outside US | Top News | Yahoo: General | Yahoo: Legal | Yahoo: Outside US

About The Author: Greg Sterling is a Contributing Editor at Search Engine Land. He writes a personal blog Screenwerk, about SoLoMo issues and connecting the dots between online and offline. He also posts at Internet2Go, which is focused on the mobile Internet. Follow him @gsterling. See more articles by Greg Sterling