[arthur_pryor]

like... i get that this is technically true, but you see how the addition of an infrared camera to the mix makes things much more cumbersome? or rather, do you see how obviating the need for an infrared camera makes discovering the password much easier (because you don't have to acquire and place an infrared camera, you're just handed the info via the visible spectrum)?

clever trick with the infra cam, but i don't think you've showed the equivalence of the situations in any practical sense. maybe that wasn't your point, and you were just offering a sorta-similar-but-not-really detection technique?

[bluGill]

The infrared camera is not something exotic. Anyone who is interested in discovering passwords will have one. Most people do not care - if I would post my bank account password here most people wouldn't attempt to login to see if it was real, and of those that do most wouldn't do anything bad. I still don't post my bank info because of the tiny number of people who would abuse it: they are mostly the same people as who would buy the infrared camera.