NEW YORK (CBSNewYork/AP) — Law enforcement groups have been saying that a police tracking feature on the traffic app Waze puts officers in danger – but an expert said demanding that Google do away with the feature is unrealistic.

As CBS2’s Dave Carlin reported, Waze allows anyone with the app to share traffic information, including where officers are. As Waze user Adam Hoggatt showed in an online driving demonstration, icons showing a cartoon police officer with a mustache pop up all over the maps.

Waze, which Google purchased for $966 million in 2013, and the app is considered 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

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

But NYPD Commissioner Bill Bratton said he is not ready to make a similar demand about doing away with the police icon.

“Some of the concerns that have been voiced about the capabilities, I’m just really not up to speed on that,” Bratton said.

Technology allows the NYPD internally to know where each officer is, but many throughout the department do not like the idea of the general public having that same ability.

But retired NYPD detective sergeant and crime analyst Joseph Giacalone said police need to live in the present-day world of technology.

“This is the 21st century,” he said. “Police departments need to adapt to this new technology.”

Giacalone said he does not see apps or icons being disabled based on police demands.

“They’re going to have to get used to it, because this is not the first app to do this. There’s going to be many more coming after it,” Giacalone said.

A spokeswoman for Waze said the app was created with input from police departments, including the NYPD.

“Police partners support Waze and its features, including reports of police presence, because most users tend to drive more carefully when they believe law enforcement is nearby,” spokeswoman Julie Mossler said in a statement.

Reports surfaced at one point that Ismaaiyl Brinsley had actually used the Waze app to track police before he killed Ramos and Liu. Brinsley had the app on his phone, but investigators now believe he found the officers randomly without using it.