I have vague memories of seeing a story sometime in the past 6 months or so about a search technology that picks up and analyzes genetic materials from stray cells as people walk through it, without ever physically touching the person. Does anyone know what I’m talking about? I’d be grateful if anyone else remembers this and can shoot me a link, either in comments or via e-mail. I also recall hearing something on BBC radio a while back about a computer program that would search for and identify pirated software or music or some such thing. Pointers on that would be appreciated as well.