This has parallels with the secret groundbreaking military technology that "60 Minutes"[1] was talking about in 2008. When you have unlimited capacity to store data and the processing power to tag objects (or people!) in real-time when you play it back, all kinds of new possibilities arise for software or surveillance (good and evil).

My assumption is that the revolutionary advance was military aerial camera systems (such as Angel Fire) that continuously record movement over an entire city in high resolution. When something happens, you can play it backwards to see who drove or walked where, who met whom, find all the connections between people, and trace events to the beginning.

[1] http://www.cbsnews.com/stories/2008/09/04/60minutes/main4415...