A motivation sensing device. It works similarly to a lie detector except for a few changes. First, you don't have to hook it up to someone. It could be a little hand-held scanner, in a pair of glasses, etc. Secondly, it doesn't sense whether they're lying or not. It senses if they have malicious intentions in whatever they're doing or saying at any given time.
Mmm... Everyone has malicious intentions. We just dont act on them. There is a little thing called common sense. Its kinda like how we dont have free will.