School cellphone searches test boundaries of students’ Fourth Amendment rights

It's happening at schools across the country: A student is caught misusing a cellphone on campus, and administrators seize the phone and look at everything inside of it.It happened last week at an upstate New York high school, where a 14-year-old boy and his girlfriend are now under criminal investigation after a school principal discovered "inappropriate" photos of the girl while searching the boy's cellphone.Is this legal?