Diminished Reality is a real-time video processing system that can erase objects from live video. The demo only looks at stationary objects, which I suppose is the limitation so far, but I suspect it will not be too long before it can remove people from video. The upshot of this is a new nifty feature for script writers to incorporate into their next heist movie.
Mokalus of Borg
PS - The thieves just need to load the software into the security system.
PPS - And selectively erase themselves, of course.