In my neck of the woods, we have a huge problem with hogs. You can actually make a living just going from rancher to rancher offering to trap or kill hogs on their place.
On the way to my family ranch, you are welcome to kill any hog you see on the trip there. Doesn't matter if you are shooting across fence lines, they just want them dead. They destroy the grazing fields rooting up the grass. It makes it murder on your back to have to shred down the weeds with the tractor. Beats you to death. Walking through the regrown grass isn't fun either. Break your ankle if you're not careful.
There is also a local guy that has some kind of deal with exporting the live hogs for Japan, wild boar is a delicacy I guess. You trap them live, take them to him and he will give you $0.25 a pound if it's over 100 lbs and $0.40 a pound if it's under (smaller hogs aren't so damn tough and chewy) Helped a friend haul some hogs over there and walked out the door with about $1500.
It's still easier (and more fun) to shoot'em though. Just have to trap a few every now and then so you can afford the ammo later.