So in my travels today, I found this. It's a 1.5m long, coiled, USB A male to USB A male cable. And I can't for the life of me figure out what it's for, other then potentially damaging the two devices you plug into either end of it!
I'm aware that there was a standard for an obscure "USB network" type device - USB A male on both ends for connecting computers together (wonder if there's Linux driver support for something that obscure? Has to be). But that requires intermediate circuitry to do - this is just a straight cable, USB A male to USB A male. If you have any idea what it's for, share your thoughts in the comments!
EDIT: Apparently there is a bunch of dodgy hardware out there that does use this sort of cable to connect to a PC! Thanks to the Hackaday commenters for the reports.