On February 2nd, the New York City Police Department sent Google a cease-and-desist letter, demanding that it remove a popular function from its Waze navigation app that allows drivers to share and avoid the locations of police checkpoints.  “Individuals who post the locations of DWI checkpoints,” the letter stated, “may be engaging in criminal conduct[,] since such actions could be intentional attempts to prevent and/or impair the administration of the DWI laws.”

The NYPD’s letter heads off years of complaints from law enforcement officials around the country that users threaten public safety when they leave comments in Waze identifying upcoming checkpoints and speed traps. The subject became a matter of widespread debate after the media discovered that Ismaaiyl Brinsley, the 2014 shooter of two New York City police officers, had advocated using Waze to identify the location of police officers. Los Angeles police chief Charlie Beck spurred further debate when he wrote a letter to Google in the aftermath of the Brinsley shooting criticizing the police locator function and asserting that Brinsley had monitored police movements with Waze in the days before the attack. The National Sheriffs’ Association has also campaigned against Waze, arguing that the application could empower not only drunk drivers but also kidnappers, to avoid known police locations.

Support for the practice of sharing the location of police checkpoints, however, has been widespread, and it has come from some seemingly unlikely corners. Helen Witty, the president of Mothers Against Drunk Driving, for example, argues that publicization can help sobriety checkpoints serve their primary purpose of deterrence. A more likely defender, Google, agrees, claiming that, “informing drivers about upcoming speed traps allows them to be more careful and make safer decisions when they’re on the road.”

Whatever the policy merits of restricting access to information about police checkpoints, however, any attempted restriction would be unlikely to hold up in court. As noted by Slate’s Hannah Bloch-Wehba, attempts to prevent the sharing of checkpoint locations face two legal roadblocks: the First Amendment and Section 230 of the Communications Decency Act.

The Supreme Court’s recent First Amendment jurisprudence is especially protective of speech that the government seeks to regulate on the basis of its content. Since at least 1972, the Court subjects content-based restrictions on speech to strict scrutiny, requiring that such restrictions be “narrowly tailored” to serve “substantial” government interests. Moreover, if New York attempts to prosecute individual Waze users for something like obstruction of justice, it would have to confront a body of case law that is protective of the free speech even of those who attempt to warn criminal suspects of ongoing investigations, so long as their speech does not constitute “fighting words,” or speech that invites a breach of the peace.  Obstruction statutes are particularly susceptible to challenges that they are overbroad, regulating more speech than is necessary to achieve their goal of public safety.

As for the Communications Decency Act, its Section 230 “largely shields Internet publishers from liability for content posted by the individuals who visit their sites” by distinguishing the role of the third-party speaker, as content producer, from the role of the publisher, as platform caretaker. More specifically, publishers are, under the Act, not to “be treated as the . . . speaker of any information provided by another information content provider.” One court has used this language to immunize publishers from civil liability for the conduct of third-party speakers, such as those who share “revenge porn.” By expressly preempting state and local laws that contradict it, the Act rules out the possibility of imposing criminal liability as well.

Given the legal odds stacked against the NYPD, Slate has dismissed its issuance of a cease-and-desist letter as mere “jawboning,” a public actor’s informal attempt to persuade a private actor to change its behavior when the government is unlikely to win in court.  In any case, Waze and Google Maps users are not going to lose their ability to scout ahead for police checkpoints any time soon. Only time and data will tell whether that ability saves lives or takes them.