alarm
big
broadcast
brother
business
camera
cctv
check
control
crime
defense
electronic
equipment
glass
guard
inspect
inspection
lens
live
look
observe
observer
oversight
precaution
privacy
private
property
protect
protection
record
screws
secure
security
security camera
spy
surveillance
surveillance camera
survey
technology
theft
urban
video
view
viewer
vision
watch
witness