The U.S. Supreme Court has agreed to hear a case this term that experts are calling a "blockbuster" and could have significant implications on one's expectations of privacy.

The case, Carpenter v. U.S., raises the question of whether the federal government's search and seizure of cellphone records without a warrant violates the Fourth Amendment.

The case stems from a string of armed robberies in Ohio and Michigan in 2010 and 2011. During its investigation into the robberies, the federal government applied for and obtained court orders to access cellphone location records for several suspects, including Timothy Carpenter, the lead plaintiff in the case.

The government received several months of information, including the dates and times of calls, as well as "cell site information for the target telephones at call origination and at call termination for incoming and outgoing calls." Cell site information location is the information generated with a cellphone communicates with a nearby cell tower. According to the National Association of Criminal Defense Lawyers, that information from cell towers can mark that phone's location, allowing "law enforcement to piece together past events, 9 for example, by connecting a suspect to the location of a past crime."

The court order that addressed Carpenter was specifically directed toward MetroPCS, his cellphone provider, and the company handed over 127 days of cell-site information, or location records, which showed 12,898 separate points of location data.

Carpenter was ultimately convicted in part because of the cell site location information turned over to the federal government. He appealed to the U.S. Sixth Circuit Court of Appeals, arguing the federal government violated his Fourth Amendment rights, which protects Americans from unreasonable searches and seizures, when they obtained the records without a warrant. To obtain a warrant, the government must demonstrate probable cause, a higher burden for the government to meet. But to obtain the court order, the government need only demonstrate "reasonable grounds" to believe the cell location information is relevant to law enforcement's investigation.

The Sixth Circuit Court of Appeals disagreed, and said a warrant isn't required under the Fourth Amendment. The ACLU then petitioned the Supreme Court to hear the case.

Carpenter's case focuses specifically on cell-site location information, but experts say the case forces the court to confront whether a decades-old legal theory has become outdated in the digital age.

"When the Supreme Court decides a case like this, it has ripple effects throughout society. The real decision in this case is about what the third-party doctrine is going to look like in the 21st century," said Wesley Hottot, a lawyer with the Institute for Justice. "In the new world in which we live where companies have vast amounts of data, are we going to have a legal rule where the federal government can freely get all of that, or are we going to have a more nuanced approach that says the government can sometimes get that information based on certain protections?"

Under current law, the federal government isn't required to obtain a warrant to get cellphone location information under what's known as the "third-party doctrine," derived from two Supreme Court decisions from the 1970s.

The Supreme Court said when a customer gives information to a third-party, such as a phone company, the customer has lost the expectation of privacy by voluntarily handing it over to that third party. That party, the Supreme Court said, can then do whatever it wants with it, including giving it to the government.

The government has applied the third-party doctrine to other contexts, said Andrew Crocker, a staff attorney at the Electronic Frontier Foundation. That includes cell site cases, Internet searches, and records of emails sent.

But Crocker warned cell site location information, as the government obtained for Carpenter, reveals a lot about a person, and technological advancements will presumably enhance the location information collected by wireless companies.

"It's something that should concern everyone who uses a cellphone, which is everyone these days," he told the Washington Examiner. "We're all carrying these things around, and they have the capacity to paint a revealing portrait of our lives. The fact they can get that without a warrant is concerning."

In the Carpenter case, for example, location data showed on several Sundays, Carpenter made or received calls from the cell tower sectors located near a church, according to the ACLU, indicating he was at a place of worship those days.

"If you think about it, it's intuitive," Crocker said. "If I have a list of all the addresses you've been to, I can learn things about you — where you go for places of worship, what doctors you're visiting, where you sleep at night. There's a lot you can learn and infer from that."

In court filings, the federal government has argued cell site location information isn't very accurate, and said Carpenter "has no legitimate expectation to privacy in the business records his providers made of the cell towers used to route calls to and from his cellphone."

It's a claim echoed by the National District Attorneys Association, which said in a brief filed last week that cell site location information is "no more sensitive than other information that this Court has held [and] is outside the Fourth Amendment when relinquished to a third party for a business purpose."

Phone numbers dialed by a customer, the organization argued, reveal more than one's "presence somewhere within an area covering many dozens of city blocks."

But Hottot said technology is likely to evolve quickly, making it possible that one's location can be pinpointed more specifically than to "dozens of city blocks."

"The arch of this technology is such that in not too long, you're going to be able to place someone within a particular room in a house," he said. "That can reveal sensitive information such as whether me or my wife are having an argument, and I'm sleeping on the couch. … The government says don't worry about it, this isn't really that invasive, but we all know that technology changes in a way that we can't predict today."

In addition to raising concerns about the government's ability to obtain location information about citizens, Crocker also sounded the alarm on the legal arguments the government has used to obtain cell site location information, which he said can apply to a wide range of devices and services consumers use today.

"This Internet of Things has this vast range of devices you interact with and generate information," he said. "That kind of information, because you've exposed it to your Nest, your Fitbit or whatever, it currently isn't protected by the Fourth Amendment, so [the government] doesn't need a warrant to get it."

The Supreme Court's decision to hear the Carpenter case has brought together a diverse coalition of stakeholders, from tech organizations such as the Electronic Frontier Foundation to civil liberties groups such as the Institute for Justice to constitutional and technology scholars.

Fifteen tech companies, including Verizon, the nation's largest wireless provider, Facebook, Apple, and Google filed an amicus brief with the Supreme Court in August backing a requirement for law enforcement to obtain a warrant for cellphone data.

"[T]he court should refine the application of certain Fourth Amendment doctrines to ensure that the law realistically engages with Internet-based technologies and with people's expectations of privacy in their digital data," the companies wrote in the brief. "Doing so would reflect this Court's consistent recognition that Fourth Amendment protections, governed as they are by reasonable expectations of privacy, must respond to changes in technology that implicate privacy."

Both Hottot and Crocker said they believe the court is going to recognize the fast pace of technology, and said the justices are attuned to how the technological landscape has changed since the 1970s.

That shift, Crocker said, could indicate the justices will look at how the issue of warrantless searches impacts society more broadly.

"I think they recently have been pretty alert and aware of that problem, the increasing pace of technology," he said. "Cellphones are different than diaries. I think it's hard to predict, but I think the Supreme Court will pay attention to that problem."