A standard feature of sci-fi and/or paranoid ravings, its the idea of an artificial satellite in space with a powerful laser, able to vaporize things on Earth at the command of the military/government/secret cabal.

A rather nice illustration of the workings of an Orbial Laser can be found in the anime movie Akira, during the scene where the two main characters, Kaneda and Tetsuo are fighting. At one point, an Orbital Laser fires at Tetsuo, vaporizing his arm. Of course, Tetsuo uses his psychic powers to fly up to the satellite (as I remember it), and take it out.

If Mapquest is able to give you aerial photograph images of most places in the USA for free, you'd expect that someone somewhere has an orbital laser.