Quoted from LTG:That is the key. Make it hard enough so they go elsewhere. Or what ever you are protecting isn't worth their time. The average home owner won't attract a safe cracker.
The guy who sold me my first ADT system told me this:
"You know those 'caper' movies? There's some painting or diamond or something in a museum with a million-dollar security system, and some plucky band of crooks steals it anyway?
If someone wants to break into _your_ house, you can't stop them. _We_ can't stop them. All we can do is make loud noises and call the authorities so they don't stay in your house very long.
But, your average thief just wants to break into _a_ house. They're looking for cash, and jewelry and small electronics they can turn into cash. Make your house more difficult or more risky, and they'll break into the house next door instead.
It's like the old joke about being in the woods with your friends when you all spot a bear. You don't have to outrun the bear - you just have to outrun your friends. We'll make your house a tougher target than the ones on either side, and nature will take its course."
(FYI, the house next door to me, identical to mine but the _one_ on the block with no alarm system, was broken into _twice_ before they got wired up.)