For the photocopier worriers, here's what my mate had to say:
"All modern MFDs [MultiFunctional Devices] are digital. The image is scanned to a CCD/image processor which temporarily stores the image as data before it being written by laser onto the drum. Basically it works like a scanner for your PC and then a laser printer.
However, if the reason behind the question is a security related one - no data is left behind in the MFD when copying. This may be different for printing where most MFDs now have hard drives containing an operating system and space for spooling print jobs. As you know, anything on a HDD can be recovered at some point in the future. Canon [who he works for] now offer security kits for this situation though which encrypts the data thus preventing any recovery of usuable data."