Yes, document holders. Those rectangles of plastic suspended over one's desk on a bendy arm that are supposed to assist you as you type by, well, holding documents. But it seems they are cunningly designed to frustrate, annoy and even injure, without at any time providing any sort of physical support for paper items. I did think their sole purpose was to periodically tip your work onto the floor, but the reality is much more sinister. You only have to attempt to move them slightly, and they will bomb your foot with a block of lead heavy enough to secure an aircraft carrier (but strangely unable to stop a weightless piece of plastic from tipping over on your desk). As if to reinforce the maleficence, you notice a tiny legend embossed on the base as you pick it up, taunting you with the words "Warning! Base is heavy".
I make no further comment. Alles ist schlecht.