It's gotten to the point that we delegate laptop trolleys to departments to manage, if they find damage it's in their interest to report it as soon as possible and manage the student(s) who caused it. We have around 400 laptops available for student use, not including Sixth Form so we can't check them each day as there are only 2 of us and honestly we have better things to spend our time on.
We also don't bother with extended warranties anymore, vandalism ends up voiding them anyway.