Depends on what you mean by misuse.
If it's a qn of print-job size, use a shared dir and write a small daemon that checks filesize before submitting to printer.
(Unless there's an option like that (size) in CUPS already).
If it's a qn of inappropriate content, have them do the same, but you'll have to check it manually :-(
If you make them email it to you, that'll make checking easier (GUI) and you can set the email system to only accept a max email size; quite common at work places.