Very interesting project. Via acoustic detection, the product aims to detect illegal usage of drones.

The usage cited are:

1. Smuggling of illegal contraband into prison

2. Illegal taping / paparazi usage

I am very surprized that no paparazi has used drones extensively. Surely you get much better angles than if you were hiding in the bushes (e.g. if you wanted to get an exclusive shot of Prince Willaims)