Viper responder alarm! The alarm triggers the remote with a signal that someone is breaking into the car (or just hit it in the parking lot). This as well as the alarm going off usually deters people. They see the blue light, see the stickers and move on to another unsecured vehicle.
If they continue to break in, and you are signaled, you can respond and welcome them with a SIG (that's what I do).
Two kids last year broke into my Vette, the responder notified me, even though I could not hear the alarm. When I confronted them, one turned on me with a large screwdriver in his hand. He froze when he saw the black object in my hand that was pointed at his chest. Police arrived, and backed up what I told the young man. Turn on someone with a dangerous weapon, and they can shoot. He was lucky. I"m only hoping that his looking down the barrel of a .40 caliber for about five minutes might change his life for the better.
Before someone says something, I know criminal laws quite well; part of my job. No you cannot shoot someone for breaking into your car/truck; except in TX (not sure about now, but used to be legal); however, if they turn and move toward you (especially if under 21 feet) with what is considered a dangerous weapon (e.g., large screwdriver, knife, hammer, baseball bat, etc.), you have reasonable fear that your life is in immediate danger, and you can defend your life with deadly force. Been there; done that.