A lot of good points have been made. Technology continues advancing whether it's used legally is up to the consumer... radios, cell phones, game cameras, ATVs, bait, electronic calls, etc all seem to share the same risks for questionable use in the field.
Until I saw this LTO on the Leupold website I hadn't looked into thermal imaging tech, so I can't speak to the intended uses of such, but it did strike me as a not-at-all-inexpensive way to check for bears or bobcats around the hen house at night. And while camping I know my children could burn through some batteries having fun with it. I could see this taking some of the fun out of a game of paintball, but don't see how it would be an aid to me while rifle hunting (assuming it were legal).
On a side note, I'm curious whether this type of technology is being researched by the insurance industry (merging with the vehicle collision avoidance controls already being built into cars) in order to reduce deer/animal impacts? Sorry, that's not really related to the original subject...