In Missouri it's against the law to bait period.
My question is how did you know they were putting out huge piles of corn?
Here's my experience with leased land for hunting.
We have a neighbor that leases his land for hunting, the problem is his land is barron, he's raped the land of every tree and piece of cover that was on the land, so there's not much on his land to hunt.
So the guys that lease his land put their stands right on the fence line of the surrounding neighbors who have not raped their land of all the cover.
They shoot deer on neighboring land and cross the fence to retreive the deer they shoot.
My brother and I hunt an 80 acre piece that is heavy with timber and brush, so the deer hole up in there because it's the only cover on that section.
This year we caught one of the hunters that had the surrounding land leased shooting a deer on us and climbing the fence to get his deer.
We confronted him about it and he wanted to give us the deer.
We told him to keep the deer but the next time we catch him or any of his buddies that are leasing hunting rights on the other land on our side of the fence we will call the sheriff and have them arrested for trespassing.
As for baiting and food plots to attract the deer, I would say there's a very fine line between the two.