A University of Colorado professor secretly photographed students, faculty members and others walking in public in order to improve facial recognition systems, prompting accusations of privacy abuse and poor ethics.

Professor Terrance Boult secretly photographed thousands of campus students, employees and visitors on public sidewalks at the university's Colorado Springs campus in 2012 and 2013, using a hidden camera set up in a building nearly 500 feet away. The aim was to improve facial recognition, especially for long-range or surveillance applications.

In 2016, Boult posted the Unconstrained College Students (UCSD) online as a publicly downloadable dataset of people acting naturally in public. Of the 2,400 people captured, more than 1,700 were considered “matched identities” - meaning the same person was snapped more than once - and of good enough quality to be used in the study. 

The project, which received funding from a number of US intelligence and military operations, including the Office of Naval Research, Special Operations Command, and the Office of the Director of National Intelligence, also included a competition for researchers to see if they could correctly match the faces using the developing software.

The project was uncovered by the Colorado Springs Independent in May 2019, a month after the dataset had been taken down. The expose ignited a firestorm amongst the local media, which focused on its opacity and intrusiveness.