Search queries may reveal quite sensitive information about the querier. Even though many queries are not directly associated with a particular person, it has been argued that the IP addresses and cookies of the users can often be sufficient to figure out who the querier is, especially if tied to information from ISPs regarding IP address assignments at the time of the relevant query. Given that the queries have been subject to discovery both by various governments and third parties, there has been great concern for how to keep such queries private. A typical approach to such privacy legislation, especially in Europe, has been to require either destruction of the data so that it is no longer available for discovery, or anonymization so that it cannot be associated with a particular person. This solution has never been proposed for personal data such as medical information used by doctors or financial information used by credit agencies. Instead, there seems to be an assumption about these types of data that their long-term storage is necessary and/or beneficial to the individual associated with them, or at least to society at large. The framework for maintaining the privacy of these data turns on safeguards where it is being held, user control of its retention and accuracy, and strict legal limitations regarding its discovery. This article briefly reviews a few legal frameworks for data protection both in the U.S. and in Europe. It presents several arguments that the deletion or anonymization of search query data is problematic, and describes a framework similar to the way we handle health data that is more beneficial to all stakeholders. Such an approach would lead to a more uniform solution to data protection in which maintaining search query privacy would not sacrifice the benefits of long term, confidential storage of the data.
Ron A. Dolin,
Search Query Privacy: The Problem of Anonymization,
2 Hastings Sci & Tech. L. J. 137
Available at: https://repository.uchastings.edu/hastings_science_technology_law_journal/vol2/iss2/1