Realistically we should all know our basic human rights and when they are being violated.
It may be legal to strip search students, but like many other situations, it doesn't mean that there isn't laws protecting students from the right to refuse a strip search. Students also have the right to request a police officer be present or even perform the strip search. It may very well be legal for a principle to order a strip search, but be just as simple for the students to claim its a privacy violation and make it a big deal.