Biostamp electronic tattoo

Motorola is looking at alternatives to traditional passwords in a bid to make logging into online sites, or accessing mobile phones, more secure.  Given that it takes 24 hours to break any 8 character password. These bio stamps, developed by Massachusetts-based engineering firm MC10, contain flexible electronic circuits that are attached to the wearer's skin using a rubber stamp. The device could then be used to confirm the owner's identity and log them in to accounts automatically.  This would prevent thieves and other people from being able to access a phone, or individual apps on the device, if it is stolen or lost.  If you are not there…. However –

·         like any tech I assume it can be scanned and copied
·         how do you deal with interference, jamming?
·         how will it cope with a high power transmitter?

Therefore does it actually solve a problem or not?  Not sure it does but interesting thinking that the movement of 5 mm from your wallet to your skin builds a reaction.