Los Angeles invaded by Drones

In the months ahead, the Los Angeles County Sheriff’s Department will test an unmanned, remote-controlled surveillance plane. If deputies want a bird’s-eye view of a standoff, they might scramble the unmanned drone instead of a helicopter to get a closer, quieter look. Within minutes, real-time color video would be streamed to a portable computer system manned by an officer 250 feet (76 meters) below.

This sounds like something from a sci-fi movie. Why they could be a huge benefit though, is that they cost less than a helicopter, especially after taking fuel and maintenance into consideration. How long until we see this in other cities?