I noticed that if people use a networked printer, they have to run to the device in question in order to stop others reading their top-secret material (or notices of their forthcoming village fete).
Today’s invention is therefore a security-enhanced network printer.
This can be set in secure mode remotely by a user. Printed pages they then generate are directed into a locked tray. Each machine would have several such trays, each with an electronic keypad to allow access to the hardcopy in question.
The machine itself would generate a new lock PIN every time secure mode was entered and transmit this by email to the author so that he/she could approach the machine in due course, at walking pace.
The paper could then be extracted without being seen by anyone else (and without obstructing anyone else’s printing work).