In one of the most significant Fourth Amendment rulings ever handed down by the Supreme Court, all nine justices agreed in an opinion involving two companion cases, Riley v. California [PDF] and United States v. Wurie, that police generally need a warrant before reading data on the cell phone of an arrestee. This decision may well presage how the court will rule on the constitutionality of the National Security Agency (NSA) metadata collection program when that issue inevitably comes before it.
The Riley/Wurie opinion provides insights into how the court will decide other digital-era privacy issues. Roberts was concerned that "[a]n Internet search and browsing history, for example, can be found on an Internet-enabled phone and could reveal an individual's private interests or concerns—perhaps a search for certain symptoms of disease, coupled with frequent visits to WebMD." The Chief Justice could have been describing the NSA metadata collection program, which requires telecommunications companies to produce all of our telephone communications every day. Although the government claims it does not read the content of those communications, it does monitor the identities of the sender and recipient, and the date, time, duration, place and unique identifiers of the communication. As Roberts pointed out in the cell phone case, much can be learned from this data. Calls to a clinic that performs abortions or visits to a gay website can reveal intimate details about a person's private life. A URL, such as www.webMD.com/depression, can contain significant information, even without examining the content. Whether we access the Internet with our cell phones, or with our computers, the same privacy considerations are implicated.
