WIRED discovers computer forensics, with a short article (and some good photos) here.
I toured a similar lab when researching Mechanisms. At one point, as we were preceding through a large room filled with people working in cubicles, I noticed that a set of blue rotating bubble lights had been lit. I asked what they were for. "They're for you," my escort said; this was the signal that visitor was in the room and that any sensitive material needed to disappear from screens.
Thanks to GHW for the tip.