Is faking a credit card number illegal?

Assuming that you are asking seriously, just think for a minute. Why would you fake a credit card number? More than likely isn't it in order to 'purchase' something when you don't have your own money? It is not likely that you will fake a legitimate number, and if you do you will certainly not be able to provide an authorized signature. But say that you can pull it off. Isn't it clear that this is stealing?