I don't need to wear a white t-shirt, but if they passed a law banning me from doing so, I would feel that those responsible for the rule were overstepping their bounds. A rule that prevented people from using cell phones in class would be sensible, but a rule saying you can't have one in your backpack is just stupid. As someone in the article pointed out, these are students, not prisoners. Your solution seems to take the opposite position.
I see where you are going, but remember that while students are not prisoners, there are many exceptions that have to be made in order to ensure the academic environment and other students' safety is met.
If cell phones are becoming a problem in schools, they should be outlawed. I do think there might be a better way, but the power needs to be in the hands of the administration here.
We all know how teens and their phones can be...