A federal court just dealt a potentially huge blow to cellphone privacy

In a potentially wide-ranging ruling, the court said that because cellphone owners technically "volunteer" their location to providers when they make phone calls, law enforcement agencies do not need a warrant to track an individual's location.

In 2010, law enforcement used cellphone locations to track and convict Quartavious Davis of armed robbery. Davis appealed, arguing that law enforcement had violated his Fourth Amendment rights by tracking his phone without a warrant.

The Eleventh Circuit Court of Appeals did not agree. In a majority decision, the court said law enforcement hadn't violated the Fourth Amendment's prohibition against unreasonable searches and seizures of property for the following reasons:

• Davis didn't "own" cellphone cell tower records - MetroPCS did.
• Davis didn't have a reasonable expectation of privacy with regard to the records.

"Those cell tower records were created by MetroPCS, stored on its own premises, and subject to its control," the majority wrote. "Cell tower location records do not contain private communications of the subscriber."

The court went on to argue that "cell users know that they must transmit signals to cell towers within range, that the cell tower functions as the equipment that connects the calls, that users when making or receiving calls are necessarily conveying or exposing to their service provider their general location within that cell tower's range, and that cell phone companies make records of cell-tower usage."

Privacy advocates contend that Tuesday's decision is based on pre-internet laws that did not envision the amount of sensitive personal data that individuals disclose. The court's decision cites two 1970s Supreme Court decisions which considered whether voluntarily disclosed bank and telephone numbers could be obtained without a warrant.

As Motherboard points out, a dissenting Eleventh Circuit judge said that Tuesday's ruling could open the door for a whole range of government tracking.

"Nearly every website collects information about what we do when we visit," Judge Beverly Martin said. "So now, under the majority's rule, the Fourth Amendment allows the government to know from YouTube.com what we watch, or Facebook.com what we post or whom we "friend," or Amazon.com what we buy, or Wikipedia.com what we research, or Match.com whom we date-all without a warrant."

The notion of privacy in the digital age is something the courts are still trying to figure out. In 2014 the Supreme Court ruled that police can't search the cellphone contents of people they arrest.

However, the 11th Circuit apparently didn't interpret that ruling to include cellphone tower data. It's possible the nation's highest court may take up the issue of cellphone privacy again.