bizwriter writes: A company announced a pilot program at Barajas Airport in Madrid to install retinal scanners to identify passengers. Passengers would presumably get their eyes scanned instead of showing documents, because the blood vessel patterns in retinas are unique to people, and so should allow for unique identification. However, it seems not only invasive, but a potentially disastrous idea that could cost a lot of money and fail to do what it was intended to. Who gets the original retinal scans for comparison? And then, when retinal transplants are possible, how do you track anyone accurately?