Being a systems manager involves dealing not only with software, but with hardware as well. We had problems of having hard disks being stolen or changed (a 40 GB hard disk was "replaced" by a 1.2 GB one...), the same happening to processors, higher speed CD-ROMs, video capture cards and memory.
We solved the problem by changing all screws in our computers -- those used to fasten motherboards, hard drives, CD-ROMs and cards -- to Bristol fasteners that need a special tool to be removed. We also changed the ones used to close the computer case. Now the technician needs four different screwdrivers to open the cases. It's a little nuisance that helps prevent those thefts. Maybe this is not the ultimate solution for this kind of problem, but it surely helped a lot!