A camera isn't safety. A camera will just tell the jury who murdered you after the fact, assuming the lighting and angle are right, that he's not wearing a mask and that his face is easy to find in some database without any possibility of false matches. Actual camera safety means a vigilant person watching with a very quick response team ready to come and help you. They don't actually do that.
Mokalus of Borg
PS - They can't afford people to actually watch what the cameras see.
PPS - That's why they got the cameras in the first place.