Jerome Greco, Director of The Legal Aid Society’s Digital Forensics Unit, was recently interviewed for an episode of NPR’s Planet Money podcast about how the New York City Police Department (NYPD) has built a massive surveillance system with very little public oversight.

Greco had begun seeing evidence of all kinds of new NYPD surveillance tools in court, but the contracts, the names of the companies, and the costs were mostly hidden.

Jerome’s team sued the Police Department and won a ruling requiring the NYPD to disclose all documents related to the purchase of invasive electronic surveillance technologies, including cellphone tracking devices and potentially previously unknown surveillance tools.

Legal Aid has published the first round of those contracts, However, the vast majority of the documentation is still forthcoming, forcing Legal Aid to consider further litigation.

“There’s a principle at stake here as well, said Greco. “Which is that you shouldn’t be allowed to hide these things from the public; it shouldn’t be acceptable, and it’s not.”

Listen to the full episode below.