Florida Supreme Court Affirms 4th Amendment Applies to Cell Phones


In a recent decision the Florida Supreme Court held that the police must get a warrant before tracking people through their mobile phones. This important decision came from the arrest and conviction of a drug dealer, who the police tracked using his cell phone.

This decision is especially important because of the language the Court used.

Officers learned of his location on the public roads, and ultimately inside a residence, only by virtue of tracking his real time cell site location information emanating from his cell phone. We are guided by the principle announced long ago that “the Fourth Amendment protects people, not places.” When that protection is violated, the Supreme Court wisely opined in Katz that “bypassing a neutral predetermination of the scope of a search leaves individuals secure from Fourth Amendment violations ‘only in the discretion of the police.’” Currently, this sole discretion of police, if unchecked by the Fourth Amendment, would extend to the more than 300 million cell phone users in America.

What about the argument that people allow their phones to transmit location data to their apps (Twitter, Instagram, Google Maps, etc.), so the don’t have a reasonable expectation of privacy in that data?

The Court answered that question this way:

Tracey had a subjective expectation of privacy in the location signals transmitted solely to enable the private and personal use of his cell phone, even on public roads, and that he did not voluntarily convey that information to the service provider for any purpose other than to enable use of his cell phone for its intended purpose.

In other words, people voluntarily allow their cell phone to transmit location data only for the phone’s intended use, and this doesn’t mean the police can then use it without getting a warrant. 

Some analysts have also written than the ruling will apply to the police’s use of Stingray devices (which we’ve written about here). Stingray devices allow, as far as we know, the police to intercept and receive cell phone communications and location by mimicking cell towers. Although Stingrays weren’t specifically addressed in the ruling, the way the ruling is written makes it clear that the Court would also hold their use requires a warrant.

Any way you look at it, this ruling is a clear victory for the protection of privacy.