As a Senior Information Controls Fellow, Zack worked with the Calipr research group at University of Massachusetts – Amherst on improving censorship detection.

The project further developed software capable of continually refining the set of web pages monitored for censorship in various countries, and for assisting with analysis of the censorship policies in these countries. Zack also published a paper assessing the geographic accuracy of proxy servers for commercial VPNs. Previous research includes Topics of Controversy: An Empirical Analysis of Web Censorship Lists.