A controller for a first vehicle is configured to, when a security system of the first vehicle is activated, transmit a vehicle-to-vehicle signal to a second vehicle, the signal comprising instructions that, when executed by a controller of the second vehicle, cause the controller of the second vehicle to activate a security system of the second vehicle. A method includes determining whether a security system of a first vehicle is activated and, if it is determined that the security system is activated, transmitting a vehicle-to-vehicle signal to a second vehicle, the signal comprising instructions that, when executed by a controller of the second vehicle, cause the controller of the second vehicle to activate a security system of the second vehicle.