Today, Yahoo upped the ante when it comes to protecting search engine users' privacy, announcing a new data retention policy providing for anonymization of search queries — as well as page views, page clicks, ad views and ad clicks — after 90 days. This announcement comes on the heels of Google's announcement in September that it would be anonymizing its logs after 9 months.
It's always good to see search companies competing to provide more privacy to their users, and with this aggressive move, Yahoo has sent a serious shot across Google's bow. Yahoo has shown that a retention period shorter than Google's — much shorter than Google's — is an achievable goal for a major search engine. This announcement should be followed by another from Google, promising to match or beat Yahoo's retention period. If it isn't, though, legislators, regulators and privacy advocates should demand an answer from Google to the question: "If Yahoo can do it, why can't you?"
Unfortunately, it's hard to gauge the true privacy impact of this policy change until we know exactly what steps Yahoo will be taking to anonymize the data. The devil's in the details, and if Yahoo's anonymization process isn't robust enough, this new logging policy may end up being more privacy PR than privacy protection. Fully anonymizing IP addresses and cookie data can be tricky, and even if that data is thrown away completely, there's still the possibility of individuals being identified based on the content of their search queries, as AOL's search data spill demonstrated.
So, as Yahoo finalizes its policy plans, it should take a look at EFF's newly-revised Best Practices for Online Service Providers, which recommends a range of techniques to strongly anonymize online user data. Hopefully, we'll see the details of Yahoo's plan soon, as well as new announcements from other search engines trying to keep up in this accelerating privacy competition. Internet users have long trusted search engines and internet portals like Yahoo and Google with the privacy of their most intimate and sensitive data, and we're glad to see those companies finally vying to earn that trust.