Points of view

Starting some weeks ago I noticed that someone tried again and again to sabotage my pc and my desk, but I couldn't find who was the smart one... Today whe I went to the new toilet on the first floor; from the top I can see my desk, because we work in an openspace, and I noticed Boss getting to my pc, and starting to do a mess on my desk and pc cables! So I realized that the "smart one" is him... I just said "ahem", and he turned round, waved to me friendly as if nothing had happened, and went away saying "Gino, come'on, back to work, you time waster". Now I always check where he is before leaving my desk..