Celebrate increased privacy: Supreme Court rules against warrantless location tracking

Happy Independence Day! Celebrate your Fourth Amendment rights, the Supreme Court’s ruling against warrantless location tracking, and the impact that may have on technologies in the future.

Celebrate increased privacy: Supreme Court rules against warrantless location tracking
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On this Fourth of July, the 242nd anniversary of the signing of the Declaration of Independence, let’s also celebrate perhaps the biggest Fourth Amendment win so far this century: the Supreme Court's ruling against warrantless location tracking.

Not only does the Fourth Amendment protect cell phone location information, but the recent Supreme Court ruling could ripple out and affect our right to privacy in regard to data gathered from Internet of Things (IoT) devices, digital voice assistants, embedded medical devices, and even devices in the future such as in-home robots.

On July 4, 1776, the men signing the Declaration of Independence could not have imagined cell phones – or that people would willing walk around holding a device capable of tracking their movements thanks to cell providers collecting cell phone location information. Nor could those men who were intent upon rebelling against King George III and declaring this nation’s independence from absolute governmental tyranny have imagined that more than 200 years in the future, the U.S. government would feel entitled to obtain that cell site location information (CSLI) without a warrant.

Thankfully, in the landmark 5-4 ruling of Carpenter v. United States (pdf), the Supreme Court dissuaded the government of its we-don’t-need-a-stinking-warrant mindset. Now, in most cases, the government must get a warrant because the Supreme Court decided that the Fourth Amendment protects CSLI.

In the words of Chief Justice John Roberts, CSLI creates a “detailed chronicle of a person’s physical presence compiled every day, every moment over years.” He added, “In light of the deeply revealing nature of CSLI, its depth, breadth, and comprehensive reach, and the inescapable and automatic nature of its collection, the fact that such information is gathered by a third party does not make it any less deserving of Fourth Amendment protection.”

Basically, the highest court in the land decided that you have a reasonable expectation of privacy against location tracking for more than six days at a time in public. If law enforcement wants to location-track you for seven days or more – get a warrant. As Privacy SOS put it, there was a “digital Fourth Amendment revolution at the Supreme Court.”

Not only is this a huge win for Americans’ Fourth Amendment rights, but the Supreme Court’s decision affects big data, which can be sensitive due to the inferences that can be made using it, and the Third-Party Doctrine, meaning even if you shared sensitive information with a third party – whether you know you agreed to do so or not – that doesn’t mean you gave up your expectation of privacy.

Effect of Supreme Court's ruling on future technologies

The ruling can also affect other current and near-future technologies under the Fourth Amendment, according to Margot E. Kaminski, who teaches law and focuses on privacy, speech, and online civil liberties.

In George Washington Law Review’s On the Docket, Kaminski wrote that since the third-party doctrine was “defanged” in Carpenter, it may impact the Stored Communications Act – which lets the government obtain emails stored for more than 180 days – as the contents of communications are generally considered to be sensitive information. Additionally, “technologies that gather location information in public places, such as police surveillance drones, now face heightened Fourth Amendment attention.”

Even more interesting is her take on what the Supreme Court’s ruling, and how that affects the third-party doctrine, could ultimately affect near-future technologies. We’ve already seen police tap into data from an embedded medical device – a pacemaker – to charge a person with a crime. Further, cops see data provided by IoT devices as fair game for investigations, such as using data from a connected water meter as well as recorded audio data sent to Amazon’s personal assistant Alexa.

Kaminski wrote:

The Court’s cabining of the third-party doctrine will also affect near-future technologies. Scholars, myself included, have rolled out disaster scenarios of how police might harness the surveillance capacities of in-home robots, the Internet of Things, or Amazon’s Alexa under the third-party doctrine. Now that scenario is far less certain. Carpenter suggests that if these devices gather sensitive information, courts will find that Fourth Amendment protections apply even if that information is shared with service providers. Both cellular phone usage and location data sharing are not voluntary in any meaningful sense, the Court found, in part because it is now socially necessary to have a cell phone. Thus, any wide social adoption of these other devices will actually now argue for, rather than against, Fourth Amendment protection, limiting Katz’s potentially slippery slope.

That may be a bit deep if all you wanted to do today was grill out, swim, drink, and watch fireworks. But however you celebrate please be sure to give at least one epic woot for the fact that you can reasonably maintain an expectation of privacy in your information that is provided to third parties. We have to take our victories when we can, and more may be on the way thanks to Carpenter.

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