Some years ago I worked in a very large firm which had corporate temperature policies. Thermostats in our work area had actual key locks on them to prevent us from changing the temperature.

The fellow in the cube next to me brought in his own thermostat and ran wires to it, and kept it hidden in his desk. For weeks the building maintenance guys kept coming by and resetting the thermostat...

I am surprised that nobody has mentioned smell.
Dogs can detect explosives, some diseases, bed bugs, and a million other things that are impossible for us.
And of course the ability to track where people/things have been would be amazing. Not to mention how it would effect are appreciation of food/drink.