You can de-authorize your own devices, if they are connected to the Sony Store via their software, i.e. your computer is connected & your reader is plugged in to the USB. However you will only be able to de-authorize that computer, not your others. Each computer will have to connect to be ds-authorized.
Only if (for some reason, e.g. your computer dies) will you need to have Sony de-authorize it. Been there.
