"
Security cameras help. They act as a deterrent. If you are going to pick a house, all else being equal, you go after the one without the countermeasures. Of course, thieves aren't the most rational people in the world either.
BTS"
Security cameras however, can be overcome by very low tech solutions. You can wear a stocking cap over your face or you can simply spraypaint the camera lens ifyou're really determined.
"This is not about guns or anything.. but I remember a tidbit of some training I had from a former employer. For ladies, because it was addressed to females. Take your hand and bend it back and shove the bottom of your palm UP into their nostrils. This will sufficiently cause them enough pain to give you a few extra seconds to decide what to do. You can also shove your heels into the top/soft bones of their feet. Take the side of your hand and hit them in mid-air."
Then there's the good old SING defense. Solar plexus, Instep, Nose and Neck, Groin. Strike those often.