New plans for monitoring people in New York City has civil liberties advocates up in arms.

The International Business Times reports:

In a speech to the New York City Police Foundation Tuesday morning, Police Commissioner Raymond Kelly announced the NYPD was working with the Department of Defense to develop a scanner that is capable of detecting concealed firearms.

The device picks up on the heat energy produced by people or objects, measured in terahertz, to pinpoint objects that are blocking that view of energy, like a gun. "If something is obstructing the flow of that radiation, for example, a weapon, the device will highlight that object," Kelly explained. "This technology has shown a great deal of promise as a way of detecting weapons without a physical search."

Is this only about detecting guns? RT reports:

What it can also do, however, is allow the NYPD to conduct illegal searches by means of scanning anyone walking the streets of New York. Any object on your person could be privy to the eyes of the detector, and any suspicious screens can prompt police officers to search someone on suspicion of having a gun, or anything else under their clothes.

CBS reports that the civil liberties groups are already concerned:

"It's worrisome. It implicates privacy, the right to walk down the street without being subjected to a virtual pat-down by the Police Department when you're doing nothing wrong," the NYCLU's Donna Lieberman said.

RT further notes:

The scanners also raise the question of whether such searches would even be legal under the US Constitution. Under the Fourth Amendment, Americans are protected from unreasonable searches and seizures. Does scoping out what’s on someone’s person fall under the same category as a hands-on frisk, though?

To the NYPD, it might not matter. In the first quarter of 2011, more than 161,000 innocent New Yorkers were stopped and interrogated on the streets of the city. Figures released by the NYPD in May of last year revealed that of the over 180,000 stop-and-frisk encounters reported by the police department, 88 percent of them ended in neither an arrest nor a summons, leading many to assume that New York cops are already going above and beyond the law by searching seemingly anyone they chose. Additionally, of those 161,000-plus victims, around 84 percent were either black or Latino. At the time, the ACLU’s Lieberman wrote, “The NYPD is turning black and brown neighborhoods across New York City into Constitution-free zones.”