NEW YORK (CBSNewYork/AP) — A New York City police union wrote a letter of protest to Google Tuesday, complaining about a feature in the Waze traffic app that allows users to pinpoint the locations of police officers.

Waze, which Google purchased for $966 million in 2013, is a combination of GPS navigation and social networking. Fifty million users in 200 countries turn to the free service for real-time traffic guidance and warnings about nearby congestion, car accidents, speed traps or traffic cameras, construction zones, potholes, stalled vehicles or unsafe weather conditions.

“Get alerted before you approach police, accidents, road hazards or traffic jams, all shared by other drivers in real-time. It’s like a personal heads-up from a few million of your friends on the road,” the Waze website says as it encourages users to download the app.

Waze users mark police presence on maps without much distinction other than “visible” or “hidden.” Users see a police icon, but it’s not immediately clear whether police are there for a speed trap, a sobriety check or a lunch break. The police generally are operating in public spaces.

But Sergeants’ Benevolent Association President Edward Mullins said in the letter that allowing users to “get alerts before they approach police” could put police officers at risk. He pointed in particular to the ambush and assassination of officers Rafael Ramos and Wenjian Liu in Bedford-Stuyvesant, Brooklyn in December as the foremost example of such risks.

READ THE LETTER

“We recognize that Google prides itself on excellent corporate citizenship and that Google believes it has the legal right to provide Waze in its current format. With rights come responsibilities, however; and the more influential a citizen is, the more responsibility it bears in exercising those rights,” Mullins said in the letter. “In using technology like Waze to publish or disseminate information, Google must recognize that the Police Icon is just a tool that, like any tool, can be used for good and bad purposes.”

Mullins wrote that he knew a Google representative has been quoted as saying the police icon on the Waze app has been discussed with police departments, but said Google has “offered an extremely weak, if not disingenuous, safety justification for the icon.”

He wrote the justifications are outweighed by “the risks to police officers from criminals who will abuse the real-time data provided by Waze, even to the extent of murder. The simple convenience to Waze users in avoiding traffic tickets pales in comparison to the risk of assassination or major crime, no matter how tenuous that risk might seem in any given situation.”

Mullins said the union was imploring Google to delete the police icon from the app, and warned that action might be taken if the company does not.

“I cannot overemphasize the importance of this issue,” Mullins wrote. “If Google does not act promptly, we will engage every effort at our means to protect the safety of our members and of police officers throughout America, including publicity, judicial and legislative means.”

Other police officials have also expressed concern about the Waze police icon.

Sheriff Mike Brown of Bedford County, Virginia, said the police-reporting feature, which he called the “police stalker,” presents a danger to law enforcement.

“The police community needs to coordinate an effort to have the owner, Google, act like the responsible corporate citizen they have always been and remove this feature from the application even before any litigation or statutory action,” said Brown, who also serves as the chairman of the National Sheriffs Association technology committee.

Sergio Kopelev, a reserve deputy sheriff in Southern California, said he hadn’t heard about the Waze app until mid-December when he saw his wife using it. Afterward, Kopelev said he couldn’t stop thinking about the app and was also motivated to act by the shooting of NYPD officers Ramos and Liu.

While attending the funeral of one of the NYPD officers, he spoke with Brown, his former boss. Brown asked Kopelev to discuss Waze at the upcoming sheriffs’ association conference. Kopelev refers to his efforts as his “personal jihad.”

Los Angeles Police Department Chief Charlie Beck also wrote a letter to Google last month, claiming the app is a threat to officers.

He asked the company to disable the police alert function after reports surfaced that Ismaaiyl Brinsley had actually used the Waze app to track police before he killed Ramos and Liu, but investigators do not believe the app was directly linked to the crime, CBS News reported.

The executive director of the Fraternal Order of Police, Jim Pasco, said in January that his organization has concerns, too.

“I can think of 100 ways that it could present an officer-safety issue,” Pasco said. “There’s no control over who uses it. So, if you’re a criminal and you want to rob a bank, hypothetically, you use your Waze.”

Waze spokeswoman, Julie Mossler, said in January the company thinks deeply about safety and security. She said Waze works with the NYPD and others around the world by sharing information. Google declined to comment.

“These relationships keep citizens safe, promote faster emergency response and help alleviate traffic congestion,” Mossler said.

This is not the first time law enforcement has raised concerns with these types of apps. In 2011, four U.S. senators asked Apple to remove all applications that alert users to drunken driving checkpoints.

Nokia removed the sobriety check tracking function of one of the most popular apps, Trapster, according to Trapster founder Pete Tenereillo. Trapster was eventually discontinued at the end of last year due to Waze’s popularity.

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