Imagine you’re a journalist, meeting with a secret government source. Thanks to the information provided by this source, you break an astronomically important story of government fraud or abuse. After the story breaks, the government decides it wants to go back and look at your cell phone’s historic geolocation information and metadata, tracking your every move and jeopardizing your source. Current Supreme Court precedent and a decision by the U.S. Sixth Circuit Court of Appeals allow government to collect this type of metadata without a warrant.

That’s why a group of 20 media organizations has filed an amicus brief with the Supreme Court, urging the justices to overturn the lower court’s order, and require law enforcement to obtain a warrant before collecting archived cell phone location data and metadata. The brief is signed by media nonprofits such as the Reporters Committee for Freedom of the Press, and media publishers like First Look Media, publisher of The Intercept.

The organizations argue, rightly so, that the First and Fourth Amendment go hand and hand. If, for example, the spying apparatus can keep close tabs on all government officials who may have material worth leaking, or whistleblowers cannot be assured that their communications and location are private, they will most certainly be afraid to speak out against government wrongdoing. This type of Big Brother paranoia inevitably has a chilling effect on speech, particularly political speech.

Carpenter v. United States, the case in which the amicus brief was filed, doesn’t initially seem to have much to do with free speech. Carpenter is an armed robbery case in which a suspect’s historic cell phone location data was used to track him over the course of 127 days. In April 2011, police arrested four men suspected of being involved in a string of armed robberies in the Detroit area. One of the four men admitted to the crime and turned over his cell phone number, as well as the numbers of his co-conspirators, to the FBI. Instead of applying for a warrant to obtain the metadata from those phones, law enforcement received a court order under the Stored Communications Act (SCA). Unlike the Fourth Amendment’s requirement of probable cause of a crime to obtain a warrant, the SCA requires only “reasonable suspicion” to get a court order.

Because law enforcement was only seeking the metadata from the cell phones, and not the actual content of conversations, the Sixth Circuit determined that no Fourth Amendment protection applied. But metadata can be just as revealing as the actual content of a phone call or text message. It can show law enforcement very intimate details, including exactly where a person was at a given time, who they called, and how long the conversation lasted. For example, if government can tell you spend most your time in Brooklyn, you shopped at Whole Foods and Nordstrom Friday after work and you called Planned Parenthood Sunday morning, they can tell a lot about you political, social and economic status. As the brief puts it, metadata paints a “comprehensive picture of an individual’s location and movement.”

If such a low standard is applied to suspected criminals, it’s not hard to imagine government entities taking a similar approach to suspected leakers or whistleblowers––and the journalists they choose to speak with. Such an aggressive approach would have a tremendously chilling effect on political speech and whistleblowing.

Political attacks on whistleblowers, leakers, and others who choose to speak to the media are already a reality. President Trump’s crackdowns on leakers have led federal employees to fear their conversations are being listening to by the White House and to hesitate even fielding phone calls from reporters. Not to mention, Trump has also called for the execution of NSA whistleblower Edward Snowden. And former President Obama used the Espionage Act to target whistleblowers more than any other president in United States history.

Journalists have also been targeted by government spy agencies. In July 2016, Wall Street Journal reporter Maria Abi-Habib was detained at the Los Angeles airport when returning from a wedding abroad. Department of Homeland Security officials tried to force Abi-Habib into turning over her personal and work cell phones, but she  refused, telling them to contact Wall Street Journal attorneys. She was eventually released, after officials realized they weren’t going to be successful taking her phones.

Despite all these concerning examples, there’s reason to be cautiously optimistic about the future. The current Supreme Court has been pretty good on issues of free speech. For example, in June, the court ruled in favor of allowing a band of Asian-American musicians to keep their “disparaging” band name, “The Slants,” and also ruled that states couldn’t bar sex offenders from social media sites.

If the amicus brief in the Carpenter case can convince justices that there is a First Amendment issue at hand regarding the warrantless collection of metadata, then maybe––just maybe––the court could issue a ruling that would protect both First and Fourth Amendment rights of Americans.

If government refuses to protect your Fourth Amendment rights, don’t expect it to protect your First Amendment rights. As one erodes, the other will go with it.  

Dan King is an advocate for Young Voices and a journalist residing in Arlington, Virginia. He writes about free speech, mass surveillance, civil liberties and LGBT issues. He can be found on Twitter @Kinger_Liberty.