Feel pretty safe as I've often been told I'm just a heartless *******. But, if they ever develop technology to identify people by their ***** then I'm in a world of hurt.
I wonder how hard this would be to fake? A flesh colored patch over your carotid arteries (or forehead?) that pulsed a signature via Liquid Crystal that was not your own? IR absorbing pigment to eliminate reflection? I guess it depends on what part of the body needs to be illuminated and what spot size.