NEED A PENNY TAKE A PENNY

Does anyone else think it's kind of wrong to take a bunch of pennies out of the take a penny tray when you don't really need it just so you don't get change back. Example: total comes to $16.04, customer give me a $20.00 and takes .04 out of the tray. What if somebody really needs that four cents or what if four people need one cent each. Man, we live in a selfish society.