The Chinese have deployed it in BeiJing and also at busy transportation termini
The Chinese obviously have some confidence in it as it has been running since before the Olympics.
Those well groomed young men and women, in Chinese 'hotspots', touting oversized, large screened 2-way radio's are internal security folks. A sister of one of these people said if they are looking for someone in, say, a station they can have the persons picture loaded in to the system and every sighting in the given vicinity is transmitted back to the hand-helds.
I guess the US will equip drones with this stuff, then give them a list of undesirables, then set them loose.