What's possible today?
1. Telephones: Needless to say, any tele-communications system that isn't connected to a special de-scrambler, is capable of being listened upon. Hardwire telephone lines would require tapping from a hard lined source. Cellular telephones, cordless house phones, and any other wireless equipment are very easy to listen in on with the proper equipment. Cell phones can be tracked to locations by linking cell and mini cell sites to the phone when connected.
Satellite Imaging: Satellites orbit the earth...they are moving objects which cannot remain stationary over a fixed object on earth. They look straight down and at slight angles only. They can however take momentary photos and record moving images for short durations of time. But tracking an individual running on foot from outer space from a moving orbiting satellite is not possible. You can get a sense of photos taken from satelittes by checking out
(
http://terraserver.microsoft.com ). Moving images are best made by FLiR taken from an aircraft.
3-D Imaging: Those scenes in "Enemy of the State" where the Feds were tracking Wil Smith inside a mutli-story building are computer generated annimation, and not possible with today's technology. Radio transmitters can be tracked wherever a clear radio signal can be broadcasted, but not through steel and concrete structures. And certainly not three dimensionally inside an office building.
Multi-Site Video Feed: The movie obviously went all out to scare its viewers into believing that our gov has linkable access to any and all video feeds within a given area. This would be an obvious violation of privacy rights and would require the cooperation of many civilian property and business owners.
The best thing about the movie though, was its believability. You really end up with a true sense of paranoia after watching it. What it should do to you, is realize the possibilities of an Orwellian dream come true.