"In order to fight fraud and preserve system security, Yahoo! will retain system specific data in identifiable form for no more than 6 months -- but only for this purpose. Yahoo may have to retain data for longer periods to meet other legal obligations," Yahoo said.
Yahoo will also expand the policy to apply not only to search log data but also page views, page clicks, ad views and ad clicks.
"In our world of customized online services, responsible use of data is critical to establishing and maintaining user trust," said Anne Toth, Yahoo's Vice President of Policy and Head of Privacy. "We know that our users expect relevant and compelling content and advertising when they visit Yahoo, but they also want assurances that we are focused on protecting their privacy."
Fueled by a focus on consumer privacy, regulators, legislators and advocates from around the globe have asked the industry to examine data policies with a focus on retention periods.
Earlier this year, industry Google halved the amount of time it stores personal data to nine months. Microsoft has said it will cut the time to six months if its rivals did the same.