if they installed metal detectors at my school i would be stopped literally every morning. i bring my laptop, tablet, chargers, headphones, mouse, my lanyard (which has metal) with my id card, and extra batteries for my bike lights in case i need them (sometimes i wear my backpack when traveling at night)
that and the backpack itself has metal on it too
my school has like 5 guards that have golf carts and one officer (that thinks i'm cool or something)