army
arrest
barb
barbed
barbwire
barrier
border
boundary
cage
cattle
closed
construction
crime
criminal
deterrent
electric
escape
fence
forbidden
forces
guard
imprison
interdiction
jail
locked
metal
military
prison
private
prohibited
protect
protection
protective
safety
secure
security
sharp
silhouette
steel
thorn
trespass
twisted
violence
war
warning
wire
wired
zone