@dalias An analytics system that communicates the current state of a one-bit noisy signal, which only runs on school-issued devices, and is only active in a setting where it replaces the need for shoulder-surfing, is not a "digital cop-in-your-pocket".
How about requiring that all digital cameras in school make a clicking (photo) or beeping (video) noise when in operation? That is also a system that identifies when certain functions of a multi-function device are in use. Would that be a "cop"?