I agree with the doubt you introduce about the convenience of using this technology in classrooms, @techblogger. Perhaps it could be used at the entrance to the institution, but not in the space where the specific educational act takes place. I don't think it favors the teacher-student relationship, which is the basis of the educational event. In addition, there are the dangers derived from that absolute control over individuals, which you synthesize well in the Orwellian image of the "Big Brother". Thank you for your excellent post, and @adsctly for spreading it.