A more thorough explanation:

Definition: Yank-cheating is when someone puts paper money into a vending machine, but then quickly pulls it back out before the machine can register it. This allows the person to keep the money and get free merchandise from the machine.

Example: John wanted a candy bar from the vending machine, but he didn't have any money. He decided to try yank-cheating by putting a dollar bill into the machine and then quickly pulling it back out. The machine thought he had paid and gave him the candy bar for free.

Explanation: Yank-cheating is a form of theft because it involves taking merchandise from a vending machine without paying for it. It is illegal and can result in fines or even jail time. The example shows how someone can use this technique to get something for free, but it is not a fair or honest way to obtain goods.