I have no idea where they found that sign. We have some pretty stupid people in our state but that isn't something that most people I know from that area (I have several friends from that part of the state) do not act like that unless provoked and they certainly don't just ride around shooting signs the the heck of it.
I live way up north in Iowa and any "welcome to iowa" sign that isn't on an interstate or near where people have built homes will have bullet holes in it.
It's one of America's last, great, undiscovered pass-times.