I think somebody is doing vandalism on my white oak trees. I own a couple acres and have had problems with my?

Depending on what area you live in, there are many states that are have problems with what is refered to as Oak Bores. They are insects that get into Oak trees and the end result is the tree will die from them. The trunks will look damaged and some will have a dark looking color to them. You might consider contacting your local county extension office and asking them if they can come out and take a look at the trees. They can tell you if this is the oak bores damaging your trees or not.