I think that scanning a credit card would be illegal only if you leave on the image the REAL numbers and name. If you do a scan, but then you change the numbers to something like "1234567890", or a random sequence, it should be ok. BUT, I am no lawyer, so I will not bet anything on it.

Scanning cash is of course illegal... but it's easy to do some modifications on the texture image to solve the problem. Changing some text, or mirroring the images, something that would make the image useless for an hypothetic fraud, but that would be not noticeable on the final render.

Giorgio (Ksabers)