quarters ▁( G CH Q ) ▁can ▁access ▁information ▁collected ▁by ▁the ▁NS A ▁on ▁American ▁citizens . ▁Once ▁the ▁data ▁has ▁been ▁collected , ▁the ▁G CH Q ▁can ▁hold ▁on ▁to ▁it ▁for ▁up ▁to ▁two ▁years . ▁The ▁dead line ▁can ▁be ▁extended ▁with ▁the ▁permission ▁of ▁a ▁" sen ior ▁UK ▁official ". ▁ ▁Camer as ▁ ▁Sur ve ill ance ▁cam eras ▁are ▁video ▁cam eras ▁used ▁for ▁the ▁purpose ▁of ▁obser ving ▁an ▁area . ▁They ▁are ▁often ▁connected ▁to ▁a ▁recording ▁device ▁or ▁IP ▁network , ▁and ▁may ▁be ▁watched ▁by ▁a ▁security ▁guard ▁or ▁law ▁enfor cement ▁officer . ▁Camer as ▁and ▁recording ▁equipment ▁used ▁to ▁be ▁relatively ▁expensive ▁and ▁required ▁human ▁personnel ▁to ▁monitor ▁camera ▁foot age , ▁but ▁analysis ▁of ▁foot age ▁has ▁been ▁made ▁easier ▁by ▁autom ated ▁software ▁that ▁organ izes ▁digital ▁video ▁foot age ▁into ▁a ▁search able ▁database , ▁and ▁by ▁video ▁analysis ▁software ▁( such ▁as ▁VI R AT ▁and ▁Human ID ). ▁The ▁amount ▁of ▁foot age ▁is ▁also ▁dr ast ically ▁reduced ▁by ▁motion ▁sens ors ▁which ▁only ▁record ▁when ▁motion ▁is ▁detected . ▁With ▁che aper ▁production ▁techniques , ▁surve ill ance ▁cam eras ▁are ▁simple ▁and ▁in exp ensive ▁enough ▁to ▁be ▁used ▁in ▁home ▁security ▁systems , ▁and ▁for ▁every day ▁surve ill ance . ▁ ▁As ▁of ▁ 2 0 1 6 , ▁there ▁are ▁about ▁ 3 5 0 ▁million ▁surve ill ance ▁cam eras ▁world wide . ▁About ▁ 6