imagine how many times you made a snide remark about a teacher or a principal to your peers in confidence. now, the target of your jeer will know that you're talking shit -- and, much like if they were to overhear trash talk about them in the hallways, they won't tolerate it. and so a bunch of harmless children will be caught in the surveillance net, and punished for normal behavior.
even worse, down the line you can be certain that state actors will gain access to the data sets produced by surveillance. then, in these kids' dossiers, they'll be marked as having anti-authoritarian tendencies as a result of their childhood discussions which were snooped on. throw in a social credit system, and someone may have a childhood remark following them for life.