You shouldn't take money that you didn't earn.
Scott is finishing his breakfast at a diner when he receives the bill and realizes that he doesn't have enough cash in his wallet to cover it.
Scott wants to pay for his meal.
Scott uses his credit card instead of cash to pay his bill.
Scott takes a tip left by another diner for the waitress off of their table and uses it to pay for his meal.
Scott's payment is accepted, and he leaves the diner.
Scott is caught taking the tip and banned from returning to the diner.