By reading the article I would have thought it would be possible to walk down the street while pointing at a house and the device would show if/where someone is hiding but after reading this FAQ I don't think this device is working so well as people expect.

Maybe in houses with wooden walls but not in buildings with thick brick or concrete steal enhanced walls. They even recommend to press the device against the wall/floor to get the best results. This means that the device can be used to see if somebody is behind a specific wall but not just somewhere in the house a couple of rooms away.