School polices don't prevail over the Fourth Ammendment. If a policy exists permitting or requiring the government to seize property without due process, it is unconstitutional. School have unconstitutional formal and informal policies all the time. They are routinely swatted down by courts. I would anticipate the argument in this case that "I reasonably beleived that it was a disruptive mp3 player." I have doubts about whether that argument would survive. If it did, no lawful policy gives a teacher jurisdiction to seize it by any means, and certainly not to wrestle it away from a child. The appropriate response is to say "mp3 players aren't allowed. Do you want to remain in school, or dispose of your non-compliant article." This, of course, would be done in the context of an administrative law hearing, with all the attendant rights (like the right to be represented by a lawyer, and the right to appeal). It seems like I read similar comments on Reddit every day. It must be widely believed that a school can do as it pleases if they have a "policy". It appears that many people allow the government to trample their civil rights, and even defend and encourage it based on nothing more than the notion that "Schools can do it because they said they can." Fuck what the schools say they can do. They are not your lawyer, they are your opponent. YOU get to tell them what to do. You should not trust your schoolmarm or your building inspector any more than your trust the drug interdiction cops that use fake dog alerts to seize cash from innocent people. Teachers are not experts in civil rights law, and even lawyers who advise school districts often take an "It's not illegal if nobody asserts their rights so we can do it until we are challenged' approach to interpreting the law. Usually to satisfy wingnut SJW school board members who don't care if their actions are illegal. Often these policies DON'T exclude medications. You have heard again and again about kids suffering because they can't use an asthma inhaler because it is locked in an office somewhere. Don't lift your skirt for this bullshit. Push back.