When state or local officials are sued in federal court for money damages for unconstitutional action, the plaintiff must prove that (1) what the officials did was unconstitutional, and (2) that the law making what they did unconstitutional was previously clear (so that state officials don't have to pay out of their own pockets if the courts recognize a new right). This is called "qualified immunity". Here, the Court ruled 8-1 that strip-searching a student is illegal (only Thomas dissented), but ruled 6-3 that this had not previously been clear (lower courts had split on the issue).
The next time this happens, the school officials will be liable, because the illegality of a strip-search is now clearly settled.
Thank you for making it clear...