Motion sensing devices for computer security are provided herein. In one embodiment, a security device includes a sensor for detecting movement of a computing device to which the security device is coupled, a transmitter, a processor, a memory, and instructions that are executed to receive from the sensor messages indicative of the movement of the computing device, determine if the computing device has been moved using the sensor messages, and output a warning message using the transmitter, if the computing device has been moved.