Couple years back some guys decided to light up the woods I was working in, they were volunteer firefighters and wanted to collect pay. This is no way reflects all the hardworking people who do this job everyday, just a few bad eggs. There were caught eventually and pled guilty. We got the equipment out in time, but the damages to timber cost them plenty- seemed they thought it was 'just some trees'. The timber was appraised at four times stumpage under WI law, same as timber theft. It was actually worse than theft, because it was early summer and would draw in beetle infestation, destroying the entire stand if left stand half burned and dead. The damage had to be cut out quickly.
Papermill would not accept the wood on account of the carbon in the fiber. Fortunately most of the timber could go to a local sawmill as they saw down to 6" diameter.
That same parcel has been set on fire three times on purpose since 1990, each time several acres was lost. The entire section was leveled by fire in the 60's.
I know of two cases of equipment arson here in the last 15 years, really not much considering the logging activity level here.