Motion detection systems are designed to sense and alert personnel of movement within a specified area. For data centers, which should have restricted access, a motion detection system would provide an alert when someone enters the area, indicating a possible unauthorized entry. While badge readers confirm identity when used properly, they don't detect motion or presence once an individual is inside. Locking racks prevent tampering with hardware but do not detect an unauthorized presence. Asset tags are useful for inventory but do not serve the purpose of detecting motion.