Flying drones for filming and commercial purposes are proliferating in the U.S., as you can see in the above's clip.

Drones can cost millions of dollars for the most sophisticated varieties (especially those used to gather intelligence and fire missiles in the battle ground) to as little as $300 for one that can be piloted from an iPhone.

The market for drones is valued at $5.9 billion and is expected to double in the next decade.

The only problem is that the law raises worries about their usage, as the NYT writes.