blocking
camera
careful
caution
control
crime
criminals
danger
entrance
fence
grade
information
monitoring
monitoring camera
monitoring system
notice
object
observation
outdoor
outdoors
outside
police
privacy
private
protect
protected
protection
safety
safety measures
secured
security
security measure
shield
signed
spied
spying
surveillance
surveillance camera
surveillance system
symbol
system
threat
tolerance
video
video camera
video monitoring
video surveillance
warning label
warning sign
watched
watching