Máquinas Vending

Is It True That If You Rough Up The Edges Of An Old Penny, It Might Read As A Quarter In A Vending Machiene?

I heard it on a CSI episode. They said that because the older pennies were made with more copper then they are now, they weighed as much as a quarter, and when the edges are scratched on pavement, it could read as a quarter in a parking meter. I was just wondering if this was true, and how this works. Has anyone ever tried it?