Some schools do have such a policy. Making it work is the problem. Even requiring parents to pay a fine to get them back does not limit them.
What was that the Pope said about technology?
Where my wife teaches (Forest Park..arruughh..) they have the no phones policy but it doesn’t stop the kids, every time I’m up there I count dozens of kids with bluetooth headsets or phones to their ears. They will call friends in class and if she tries to take the phone, they will call their parents (which backfires 90% of the time)...and this is a middle school...
There is technology to block cell phone signals