Here he is in 2012 at the 9th Circuit Judicial Conference (yes, THAT conference on Maui...):
Tracking the Trackers, Part 2: Tracking and the Government
(His presentation begins around 17:30 minutes into the recording.)
Here's his TedTalk:
What Borders Tell Us About The World: Mariano-Florentino Cuéllar at TEDxStanford
And here's an interview about his book, "Governing Security: The Hidden Origins of American Security Agencies." ("The book looks at the origins of the Federal Security Agency under President Franklin D. Roosevelt and the Department of Homeland Security under President George W. Bush.")