I certainly could be wrong, and I have been before (!), but I've hunted hogs for years and have never heard of them attacking people unprovoked. Now, this provocation could simply be getting between a sow and her piglets, you've jumped one and you're in its path or you have the audacity to hurt one with projectiles or sharp objects and then fail to get out of the way fast enough if you don't kill it outright. They have very poor eyesight, and when they are trying to get away, they will run over or through anything in their way. Out of a couple dozen hogs, the only one to charge me was a mean old, scarred up boar that I wounded. He started running away from me, but when I hit him the second time, I guess he'd had enough. The third (somewhat rattled) shot killed him.