The alarm and security specialists we've talked to claim the greatest threat to systems are authorized users: the property owners, their children, employees, servants, nearly all of whom fail to arm and disarm the system properly not matter how carefully instructed. A false alarm is feared by these users more than an attacker, for they are more often traumatized by an errant signal, and the outpouring of security personnel and police, than by an actual attacker. (Like the US security and law enforcement systems.) The security responders are so pissed, or so condescending, that the users are in a state of panic about the systems going off falsely. Answer to that is to leave the system off. And claim they forgot to arm it. Thus, self-censorship to keep the cops from attacking. Then there are panic room backups which freak the users due to its capability of killing them with false threats like the gentleman, Safra, was killed on the Mediterranean coast when he believed he was under attack as responders tried to rescue him. Responders are a genuine threat when they think you are an AIDS carrier. It's worth keeping in mind, that protective and security systems can do you great harm, like friendly fire and security agencies of all kinds -- banks, doctors, accountants, in-house guards, most trusted associates. Gun owners, and nations, being killed by their own weapons is a kissing cousin threat. Technology is a gun most often in the hands of those will to fire first then question who's there. WMDs are the biggest threat to the US and ilk, those owned by the panic-room trapped users. North Korea, say, or the Joint Chiefs, aided and abetted by the low-credibility spooks. Back to failure of home security systems: its the back-up batteries that don't get replaced, rather the monthly bill for service is neglected by wayward servants while the owner is vacationing on a yacht being tracked by IRS.