Two years ago, the Supreme Court upheld an injunction blocking the enforcement of the 1998 Child Online Protection Act, a law allowing the operators of online pornography sites to be punished for making their content accessible to minors. The case was sent back to a district court, leaving the government responsible for proving that the law was needed and constitutional. As part of their effort to resurrect the law, the government sent subpoenas last year to three major search engines and one online provider: Google, Yahoo, MSN, and AOL. The subpoenas requested “all URLs that are available to be located through a search query on [company’s] search engine as of July 31, 2005″, as well as a week’s worth of recorded queries. The subpoena specifically requested that none of this information was to be linked to individuals. Yahoo, MSN, and AOL complied. Google did not.

The San Jose Mercury News reported yesterday that Google is fighting the injunction, claiming that “the demand for the information is overreaching” and threatened their users’ privacy as well as the company’s trade secrets. But wait, you might say, if the records weren’t supposed to contain any information that might identify a particular user, where does privacy come in to the equation?

From The New York Times:

“Google’s acceding to the request would suggest that it is willing to reveal information about those who use its services,” it said in an October letter to the Justice Department. “This is not a perception Google can accept. And one can envision scenarios where queries alone could reveal identifying information about a specific Google user, which is another outcome that Google cannot accept.”

While this particular request does not ask for identifying information, the next one could, and there is a lot of identifying information to be had. (SearchEngineWatch has previously covered search engine privacy concerns.) Given the recent revelations of NSA domestic wiretapping and previous demands for information such as library records, it wouldn’t be surprising if they started asking for search engine user profiles as well. If Google ends up complying with the subpoena, they risk losing the public’s trust, and for a company that lives by the motto “Don’t be evil,” that’s a very grave risk indeed.

SearchEngineWatch also has some excellent posts on this story, including a summary of the court precedings as well as an ongoing commentary.

When we talk about privacy enhancing technologies we often immediately jump to talking about encryption methods and DRM technologies and instance based access controls. But sometimes we forget about techniques for minimizing data disclosure. I know I’m guilty of this. I’d much rather debate the pros and cons of various policy expression languages!

I was reminded about data minimization recently when I tried for the first time a service from my credit card company, virtual credit card numbers. With so many people experiencing credit card fraud online, I’m surprised more people aren’t using virtual credit card numbers. They are a great way to minimize the disclosures of your real credit card to others. So I thought I’d share my experience with the service so far.

Read the rest of this entry »