This is really quite frightening if it is true. Schools should absolutely not have the right to discipline students for activities that take place in their own homes or at any venue not directly associated with the school.
According to the filings in Blake J Robbins v Lower Merion School District (PA) et al, the laptops issued to high-school students in the well-heeled Philly suburb have webcams that can be covertly activated by the schools' administrators, who have used this facility to spy on students and even their families. The issue came to light when the Robbins's child was disciplined for "improper behavior in his home" and the Vice Principal used a photo taken by the webcam as evidence. The suit is a class action, brought on behalf of all students issued with these machines.