My TV has been bombarding me with commercials for Brinks (now "Broadview") security systems, which is great because I wasn't feeling insecure enough without the TV reminding me what a danger strange, scary men are.
In case you haven't seen the spot it goes something like this: Kind-looking white lady returns into her house and immediately arms her home alarm system. Scary-looking, darker-skinned, and not recently shaven man breaks down door and menaces at woman, who promptly screams and retreats into her house. Cue: brinks alarm. Scary man runs away, phone rings, and Brinks sends in the cavalry.
This ad is kind of like an impressionist painting: it appears cogent when looked at quickly and from far away but a closer inspection reveals that the details are blurry. First, thieves spend a lot of time casing out their targets and know to strike during the day when suspicion is at its lowest. They will likely not kick down doors, instead opting to pick locks, disabling the systems, cutting phone and power lines, or gain entry through open windows and side doors. They will be after specific targets like cash, jewelry, and electronics and will make quick work of collecting them. Before the police are even dispatched, they will probably be long gone. Second, alarms are largely over rated. How many time have you heard a car alarm go off and not called the police? My guess is about every time. Professional thieves are likely not afraid of loud noises and will simply continue with their plan as quickly as possible. Three, only the most paranoid home owner would turn on their security system the moment they entered their house, instead choosing more likely to leave it off while home and on only during periods of extended absence. Third, in cases of malice towards the individuals of the house, a security alarm would be totally ineffective. One spot shows an ex-lover breaking into a woman's home, being scared away by Brinks's assuring siren. In that kind of case, the ex-lover would probably know about the alarm in advance (probably even how to disarm it) and would still have the time to harm, kill, or kidnap the victim before Brinks even calls. And last, the mere ownership of a security system gives home owners a false sense of confidence that will likely cause them to be more reckless in other areas of basic property protection.
Most would-be criminals would likely be deterred by the security sign posted out front, and those who aren't are going to be a lot more resilient again Brinks's loud noises and response phone calls. My advice, build a sturdier home. You won't need Brinks if it is physically impossible for a criminal to break-in in the first place.