against
air
aluminum
aspect
backdrop
background
bondage
brutality
captivity
cell
closeup
crime
defense
enclosure
eye
fear
fence
ferrous
fireguard
freedom
grate
grid
guard
horizontal
iron
isolated
jail
lattice
metal
metallic
miserable
net
netting
nobody
old
pattern
prison
protection
railing
regular
rusty
security
shelter
sight
slavery
sly
steel
texture
totalitarianism
tree