Montana has taken a major step forward in protecting citizens’ privacy, closing a loophole that allowed law enforcement to purchase data from data brokers.

US law requires law enforcement to obtain a warrant to gain access to certain information, especially sensitive information like your location. If obtaining a warrant is not practical, or if police feel it would be too time-consuming, a popular option is to bypass the judiciary altogether and simply purchase the data from a data broker.

As the Electronic Frontier Foundation points out, Montana has become the first state to close that loophole and prohibit law enforcement from doing an end-run around the warrant process.

In every state other than Montana, if police want to know where you have been, rather than presenting evidence and sending a warrant signed by a judge to a company like Verizon or Google to get your geolocation data for a particular set of time, they only need to buy that same data from data brokers. In other words, all the location data apps on your phone collect —sometimes recording your exact location every few minutes—is just sitting for sale on the open market. And police routinely take that as an opportunity to skirt your Fourth Amendment rights.

Now, with SB 282, Montana has become the first state to close the data broker loophole. This means the government may not use money to get access to information about electronic communications (presumably metadata), the contents of electronic communications, contents of communications sent by a tracking devices, digital information on electronic funds transfers, pseudonymous information, or “sensitive data”, which is defined in Montana as information about a person’s private life, personal associations, religious affiliation, health status, citizen status, biometric data, and precise geolocation. This does not mean information is now fully off limits to police. There are other ways for law enforcement in Montana to gain access to sensitive information: they can get a warrant signed by a judge, they can get consent of the owner to search a digital device, they can get an “investigative subpoena” which unfortunately requires far less justification than an actual warrant.

Interestingly, as the EFF points out, this is not the first time Montana has taken a pro-privacy stance one would expect from a state like California, Washington, or New York.

Despite the state’s insistence on honoring lower-threshold subpoena usage, SB 282 is not the first time Montana has been ahead of the curve when it comes to passing privacy-protecting legislation. For the better part of a decade, the Big Sky State has seriously limited the use of face recognition, passed consumer privacy protections, added an amendment to their constitution recognizing digital data as something protected from unwarranted searches and seizures, and passed a landmark law protecting against the disclosure or collection of genetic information and DNA.

The data broker loophole has been a hotly debated topic, with critics arguing that it provides law enforcement a way to do an end-run around the Constitution. Privacy advocates say it undermines rights enshrined in the Constitution and makes it far too easy for abuses to occur.

There have been numerous attempts to curb the practice, most notably Senator Ron Wyden’s H.R.4639 bill. Despite being introduced over a year ago, the Senate has yet to consider it, leaving individual states to tackle the problem.

Montana’s new law provides tangible privacy protection to its citizens, and helps prevent what is often described as an unconstitutional practice by law enforcement. With Montana taking the first step, it’s probably only a matter of time until other states follow suit.