I don't know if others do this but AFTER gutting the deer I always cut open the stomach and see what they were eating. Last week we shot five deer and four of them had corn in their stomach's and mine had crab apples, which a lot of them were never even chewed. The nearest cornfield was at least a mile away.
The nearest pile of corn may have been much closer. Sorry, I know deer can travel a good way but I do believe baiting/feeding is a problem.
Usually don't open the stomach on deer I harvest but when I have they have had corn in them which is too be expected since most are archery season harvest and there are many nearby cornfields still standing.