You really think that cutting a timber company's logs without permission is okay just because you want some firewood ?
First of all, you're breaking the law. If you're on the timber company's land without their okay you're trespassing. If the logs you cut are length prescribed for milling and are devalued by the removal of any of their length you've committed vandalism. If you take the wood you've cut, you're a thief pure and simple.
A lot of people have an attitude like yours. That's one of the reasons that we had to ban firewood cutters from our ground. The majority of firewood cutters are probably alright but people like you give us problems that we don't need.