In an ongoing battle to give users the most privacy, Yahoo has set their data retention threshold at 90 days. This means that “Yahoo! will anonymize user log data within 90 days with limited exceptions for fraud, security and legal obligations. 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.”
Google is currently sitting at 9 months before data is made anonymous, down from 18 months. That was in response to Yahoo! dropping down to 13 months in July 2007.
As for the exceptions Yahoo said:
“To protect users and our business partners, there will be some specific and limited exceptions to the anonymization policy. 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.”
It remains to be seen if Google will fire back with an even shorter time frame, but Yahoo! claims that 90 days is a minimum for business purposes.