Calling them hunters is akin to calling a carjacker a driving enthusiast. They are thieves and poachers. A kid shot a big 10 point with a rifle on the farm I hunt. It was August and he was trespassing. He was fined but I don't believe he lost his license. I hope they get fined and jail time and additional charges get piled on. Trespassing would be appropriate.
I am not sure if the laws have changed. I think if the DNR witnesses the act they can confiscate the vehicle and weapons for a start and then add on fines. I think the same law is in affect in fish poaching, they can convict you of it after the fact, but if they don't witness you doing it from the boat they can't confiscate your boat. However, i could be totally wrong, and they can't be everywhere, especially after all the budget cuts at DNR.