Amazing how easy it is for anybody to get hold of sensitive data. I am not sure what is the purpose of a hard disk in a copy machine. They should not have these. The copy machine wants extra money for deleting images or encrypting.
In short: the disks are needed to hold multi-page scans - think collating multiple copies, double-sided printing, etc. The problem is that normal file-system deletion is not a secure wipe, and files can be recovered with simple tools.