This chair had the top section of the arm removed by Jacob_M on instructables.com. Then he cut out a hole beneath the arm to reveal a large secret compartment inside. This doesn’t work on all couches, but some are waiting for someone to get the jigsaw out.
OfficeAnything sells this office chair with a secret stash compartment in the back. This is one solution to inconspicuously hide critical items and documents in the office without putting it all under lock and key.