I concur with TC17's response. There should be zero tolerance for this kind of vandalism, tampering with a safety feature, creating an unsafe work condition/circumstance, and blatant waste of company time.
Sadly, the same operator mentality that is the root cause of stuff like this is quite common in the occupation.
Regarding the "too much time on my hands" remark. How true!
Many years ago on our dock, one of our fairly new (then) Komatsu FG20ST-12s was repainted completely (including wheels and tires) to "John Deere Green" by what must have been a "team effort" using spray can paint (which was pilfered from a damaged shipping carton that had been placed in the damage claims holding area). One has to wonder why the supervisors on duty did not get skewered for allowing something like this happening on their watch. To my knowledge the culprits were never identified (thick as thieves crew) and management back then did not even seem too concerned about it. In fact, it was our shop mechanics who had to report the incident to the dock managers. Their reaction was more like mild amusement instead of a sober and serious determination to address the situation for what it really represented.