>>>By the high frequencies used in the comp and there digital nature (what ends up with even higher frequencies, look up fourier transform on rectangular function) shielding is very tricky. One CD tray out of plastic or a badly connected socket is enough. Cooling fans are a problem too.
>>
>>That's why God invented tinfoil ;-)
>
>No NO NOOOOO
>I'm not allowed to buy tinfoil anymore. Book keeping will freak out. Under EU law this is dealing with unprocessed ignoble metal. It raises endless tax problems.

Metal mosquito net works just as fine for most purposes. We've seen a guy holding his ID in a metal box... and he was a cop, in uniform. Does he know something we don't? As our ID has a chip in it, not quite sure whether it's RFID or on close contact only - the readers are usually bundled with a printer, so the printout serves as a proof of identity. Which doesn't mean there can't be other, much smaller machines, capable of reading it. Since there are no metal contacts exposed, I guess it's some kind of RFID, allegedy with very short range, yeah right. And it's actually optional - I checked the other checkbox on the form and mine is electronics-free plastic.