We know that face recognition system has been used in the field of military and a few limited, this equipment can scan streets named MORIS face, within 5 feet to sample and with data in the database at crime, if find a known suspect or scanned into the related criminal history, can help the police rapid response, there are at least 1000 sets of such equipment will come to 40 police organization in the United States, each cost up to $3000.

It quickly caused the society concern about privacy, this kind of face recognition technology is violation of constitutional rights and the principle of "beyond a reasonable doubt" criminal case is considered worthy of discussion, the police from the channels of access to the evidence is enough to convict, will bring may void the harassment claims and evidence is uncertain. In addition, the photo capture technology and court approval is not obtained, also the system basic unavailable during the night.