In April 1988, Albert Culberth of Miami ate a few grapes as he and his wife were doing their grocery shopping. An off-duty cop saw him, put him in cuffs, and took him to jail, despite Culberth’s insistence that he had every intention of paying for the grapes during checkout.
If the grapes were charged by weight, then yes, he would have been stealing. But from what I can gather, the grapes were part of a set-price pack in his cart. So if he had been given the chance to pay during checkout, the store would have had no loss. The charges were eventually dropped for that reason.