Light and pressure sensors using arduino platform

Some offices are using removable hard drives, for the reason of keeping the data on the hard drive safe from theft.
At the end the day in an office, the hard drive is moved to a safe or behind some sort of lock.
It is very common to forget the hard drive in the computer and thus leaving the secure data free for theft.
For this reason, using the arduino platform and light and pressure sensor, I have created some sort of prototype that will give an indication if the hard drive is not stored in place when the lights in the office are turned off at the end of the day.