It's not totally exclusive I think, as a cat succeeds when the player app is running, but I guess all data sent by the client is swallowed by
the player-app ( I'm not totally sure on this, will check this evening )

Received data on USB is randomly distributed over all readers of /dev/usb. I think the easiest solution is to restart the player-app with USB disabled using the quit option. A suitable init-script would be easy...

Frank van Gestel