Steven M. Bellovin writes:
> Running 'btconfig ubt0 down' doesn't turn off the light.

I think its off. Sometimes the button does the equivalent of unplugging the=
 USB device, so you would see "ubt0: detached" on the console.  Perhaps in =
your case the button does something else that we don't know about, either v=
ia ACPI or a normal keycode?

If the device is not enabled, there will be no USB transfers set up so noth=
ing will be received by the bluetooth stack. I don't know what would happen=
 if the device tried to send data anyway, if that would get queued inside t=
he USB stack or discarded.

iain