Via flyertalk, this story about a transparent bag mandate outside an airport context: Wissahickon Students Face Strict Backpack Rules
High School students in the Ambler, Pennsylvania, headed back to school Tuesday facing new security measures limiting their choice of backpacks. Effective Tuesday, all students in the Wissahickon School District are required to carry clear bags. Students are currently permitted to bring mesh backpacks to school, but once inside the building, they must change to a clear backpack. … Wissahickon is the third high school in Montgomery County to adopt clear backpacks.