From the New York Times:

Privacy is central to American law. And in 1986, Congress applied that principle to electronic communications by setting limits on law enforcement access to Internet and wireless technologies. It was a laudable law at the time, but cellphones were still oddities, the Internet was mostly a way for academics and researchers to exchange data and the World Wide Web that is an everyday part of most Americans’ lives did not exist.

The law is no longer comprehensive enough to cover the many kinds of intrusions made possible by the advances of the past 24 years. In the absence of strong federal law, the courts have been adrift on many important Internet privacy issues. The law is not clear on when search warrants are required for the government to read stored e-mail, what legal standards apply to GPS technology that tracks people’s whereabouts in real time and other critical questions.

Digital Due Process — a coalition that includes Google, Microsoft, the Center for Democracy and Technology and the American Civil Liberties Union — recently proposed a good set of principles for addressing those issues. The coalition recommends that all private data not voluntarily made public, such as stored e-mail or private financial data, should be as protected as data in a person’s home. To get it, the government should need a search warrant.