If that were the case, they wouldn't be there when you were. If someone breaks in, knowing you are there, or unconcerned about whether or not you are there, you are in danger. Yes, security systems are pretty easy to get around... and unless the home invader plans on moving in, depending on where you live, it wouldn't matter if the police are "on their way". Just cutting the lines at the NIB, and any cable lines renders most systems useless. Takes a couple of seconds. That, and one of these $39 jobs And nobody is coming to rescue you. Shotgun.