For some time while watching the movie...
I thought both Donna and Bob were civilians being used by the police to track other civilians. I had this crazy vision in my head of a futuristic government making every civilian a part of the police force, and using scramble suits to keep identities hidden. A perfect system: you YOURSELF are your own correctional unit.
I think this idea could have made the plot a lot thicker and more interesting than it already is.
As it is, I love how this movie manages to make concrete something that is constantly nagging in the back of my head, in the back of all our heads really. I can't even explain it or describe it properly but it's like there is no need for a "substance D." As a society we are already anesthesized and addicted to so many things that keep us in the loop, that we lose touch with "reality". Whatever that is.