I get enraged when people do this...
Ok, there is a lot of rude behavior out there but I see this happen all the time: a person throws down money for a cashier instead of handing it to them. This is SO rude its like " your'e so lowly Im refuse to directly touch you".
Seriously hand them the money! If someone did that to me I would throw the change back at them just to make a point.
Do you find this really rude or is it just me overreacting?