I the principal should let students use cell phones in school during their breaks only because if they have a family emergency they could call their parents and let them know that their okay, if they forgot their homework at home they could call their parents and tell them to bring to school for them.

If there was a case that happened at school and that student has their cell phone they could easily call their parents let them know that their alright because the incident could be the news and the student parents might think,

"OH THATS

MY BABY"

the principal don't want the mother of a student who goes to SCHOOL_NAME

to worry and if the student has their phone on them they could call them and let them know evry thing is okay.

Oh Snap my homework is due today before the student enter the build they could call their dad and let him know that they left their homework in the back seat of the Hummer and wait for their father to turn around and give them their homework instead of them getting an "F" on their paper because their teacher wont give them an extra day to turn in the assignment because she told them when it was due and she wants it no later then it was due.

"O.M.G my leg is broken little STUDENT_NAME" said "let me call my mother and let her what just happened so I cold go to hospital"

now that's why they should lets use cell phones in school because they may never know when a incident might occur its always good to have a cell phone on you in school because it take to long to go to the office to call your parnets and let them know what