In a decision that privacy advocates are hailing as an evolutionary step towards harmonizing the Fourth Amendment with the Digital Age, Eastern District of New York Judge Nicholas Garaufis ruled on Monday that the gathering of cell phone users' location history by government officials without probable cause is unconstitutional.

The courts have meandered on the legality of warrantless cell phone location tracking by policy enforcers. It has been argued that as long as users have their cell phones turned on, they waive any expectation of privacy by transmitting their location to a third-party.  Garaufis roundly rejected this line of reasoning in a 22-page opinion (PDF) which denied a request by the federal government that Verizon Wireless hand over 113 days worth of location data about a suspect's cell phone.

     "The fiction that the vast majority of the American population consents to warrantless government access to the records of a significant share of their movements by 'choosing' to carry a cell phone must be rejected," Garaufis wrote. "In light of drastic developments in technology, the Fourth Amendment doctrine must evolve to preserve cell-phone user's reasonable expectation of privacy in cumulative cell-site-location records."

According to the third-party doctrine, Fourth Amendment privacy protections over information submitted to or handled by businesses are extended only to the contents of communications and not to the “non-content metadata” that defines the parameters of the communication, such as the address on an envelope delivered or a phone number of a person dialed. For some time, cell phone location data has been lumped into this second, non-content legal category as “transactional information,” which is governed by a provision of the Stored Communications Act.

What this means is that law enforcement personnel don't (traditionally) need a warrant to force companies to relinquish information regarding the historical whereabouts of a suspect's cell phone – individual records of which are kept by service providers who routinely triangulate a user's position among cell towers and transmit this data on a regular basis to a company database. The only thing government officials have to do to procure this information is make a case that it's “relevant and material to an ongoing criminal investigation.”

However, Judge Garaufis ruled that:

     "there is no meaningful Fourth Amendment distinction between content and other forms of information, the disclosure of which to the Government would be equally intrusive and reveal information society values as private."

Elaborating further on why the third-party doctrine should not apply to "widely used communication technologies in which service-provider intermediaries receive and store private user information incident to the service," Garaufis maintained that "established normative privacy considerations support the conclusion that the reasonable expectation of privacy is preserved here." In other words, just because someone signs up for cell phone service doesn't mean that they then tacitly consent to a record of their movements being disclosed to government agencies.

While admonishing the prevailing enforcement orthodoxy, the judge went so far as to reference in his decision George Orwell's dys'topian classic 1984:

While the government's monitoring of our thoughts may be the archetypical Orwellian intrusion, the government's surveillance of our movements of a considerable time period through new technologies, such as the collection of cell-site-location records, without the protections of the Fourth Amendment, puts our country far closer to Oceania than our Constitution permits. It is time that the courts begin to address whether revolutionary changes in technology require change to existing Fourth Amendment doctrine.

Also on Monday, the California Assembly passed a cell phone privacy bill that would require police to secure a warrant before searching the contents of suspects' smartphones. If passed by the Senate and signed by Gov. Brown, the law would effectively overturn the January California Supreme Court ruling which allows officers to search the contents of confiscated cell phones.

Police oppose the measure in spite of Assemblyman and former police officer Steve Knight's promise that it will not interfere with the legitimate needs of police. “All established exceptions that currently exist will still apply,” said Knight. The law would still allow police to search a phone without a warrant if they believe doing so would prevent injuries, stop the destruction of evidence or prevent a crime from occurring.

     “If you are caught with a laptop, they need a warrant. If they come to your home for some reason, they can't walk into your bedroom, personal office or look at your computer without a warrant,” said state senator and bill author Mark Leno. “Everything inside your phone requires a warrant wherever else it can be found, so why should the smart phone be different?”