This. It's a sensor, detecting only a specific air type. Not a camera, not a microphone. It doesn't have to do with privacy, this is not "scan and collect data about all to punish one" and cannot be turned into one.
I'll agree it's a fuc**ing dumb idea. Like utter useless garbage. Classic capitalistic "fix behavioral trash-consumption issue with overpriced fancy tech products that sound amazing in theory and are garbage in practice, without fighting the problem at the root". Screenshot comment said tax moeny but I'm willing to bet this is some kind of private school.
Because there is too many ads