For Ingrid, a 15-year-old in La Crosse, Wisconsin, going to high school means being monitored on surveillance cameras in her hallways and classrooms. Students are required to carry their school supplies in clear backpacks, as ordinary backpacks might be used to conceal a weapon, she said. Water bottles must also be clear, so school officials can see the color of the liquid inside. The monitoring continues on the laptops students use in school. Teenagers are warned that the school is tracking what they do, and that they can get in trouble for visiting inappropriate websites.