A new project transforms the humble Raspberry Pi into a simple and affordable surveillance camera system. Using just a Raspberry Pi, Python, a motion detector and a Raspberry Pi camera, the project can email you photos if you are away from your home whenever it detects motion.
https://www.notebookcheck.net/Raspberry-Pi-Turn-the-popular-single-board-computer-into-a-cheap-and-simple-surveillance-camera-system.467604.0.html