The ultimate goal is to deter and annoy the thief. Ergo, if someone wants it bad enough, they'll find a way. In this instance, the thieves had an easy time because of the general lack of security. If there was a sign up stating you had cct, they may have moved on. It's all about opportunity cost.
The more annoyances you possess, in conjunction with the style of thievery, equates to the outcome of the break-in (from conception to completion). An alarm is an annoyance, as is a dog, closed curtains, at-home neighbors, safes, signs, lights, cars in driveway, etc. No one item is key, it's a combination of all these things that says, "move on over to someone else". Your mindset should not be "I want to stop this thief", it should be, "I want to make this as annoying as possible". If you take that approach, you'll be more successful at actually stopping them. Not to mention your overall demeanor on the subject changes, and you'll probably think of more creative and fun ways to f_uck with them.
This is my general approach. Kind of like Sean Combs in "Get Him to the Greek"... you have to mind f_ck them.