It has been, for a long time, one of THE GREATEST THREATS TO FREE SPEECH EVER KNOWN, at least when college students do it by shouting down a speaker (in most of such stories, 'shouting down a speaker' was politely protesting outside or turning their backs inside, but nevertheless...).
Letting one busybody ban all the books is, charitably, a version of that. It certainly isn't "parent control of schools" which was what all the Very Serious Pundits told us this stuff was all about approximately one election day ago.
