NYPD won't disclose what it does with its secret military-grade X-ray vans

The $825,000 Z Backscatter Vans the NYPD drives around the city look like regular police vans, but are equipped with powerful X-rays that can see through walls and vehicles. US Customs uses these things to scan cars and freight-containers, but only after they're sure there are no people around.
For more than three years, Propublica has been suing the NYPD for access to training materials and other documents explaining what the NYPD does with the vans, and even though a New York court ruled in their favor in January, the NYPD is still fighting the order in appeals court.
This week, the New York Civil Liberties Union and the Brennan Center for Justice filed for leave to intervene in the case with an amicus brief, arguing that New Yorkers had the right to know if the police were secretly looking through the walls of their homes while bombarding them with dangerous radiation.

The military-grade surveillance equipment, which utilizes x-ray radiation to image the inside of cars and buildings, is used to search for roadside bombs in Afghanistan. The NYPD has largely refused to disclose anything about how it uses x-ray vans on the streets of New York. The department denied a Freedom of Information Law request by an investigative journalist at ProPublica asking for records revealing the vans’ public health risks, the NYPD’s prior use of the vans, whether the department gets a warrant before it uses them or how long the NYPD holds on to images the vans capture. The NYPD also won’t say how much the x-ray vans in total are costing taxpayers, though reportedly the NYPD is shelling out between $729,000 and $825,000 for each unit...
...In ordering the NYPD to produce records related to x-ray vans in Grabell v. the New York Police Department, the trial court found that the NYPD did not show how disclosing information about these x-ray vans might compromise investigations. The NYPD’s refusal to disclose information is further undercut by the fact that other agencies, including the Department of Homeland Security, have already revealed the same types of information about similar technology.

NYPD Unlawfully Hiding X-Ray Van Use in City Neighborhoods, NYCLU Argues