>> most new yorkers and tourists have no idea they're being watched on rooftops or on the observation deck of the empire state building. >> looks pretty crowded. how far away are we from that? >> probably about a mile and a half. >> that's from a mile and a half out. >> that's correct. >> and i can see what she's wearing, the red scarf, the red jacket, the red hat, and i bet not one person on that observation deck has noticed you. >> nobody notices what we're doing. >> privacy rights don't allow police to look inside the apartments, but with the technology they have, it is possible. but as good as it is, the view from above isn't nearly enough.