Stupid damn printer/fax machine/copier. I put a document in to fax, and punched in the fax number. 7010 2168 (or something like that).
But I hadn’t set it to Fax mode. It decided it was in Copier mode, but will only allow three digits for the number of copies, so it started printing 168 copies of my 4 page document. Thankfully I was able to cancel the job before it used up a whole tree.
A little commonsense in the design should dictate that if someone punches in 7 or more digits, they probably want to fax, not copy.