If I was a kid in school I'd probably organize some sort of protest about this... Invite the local tv station, set up across the street from the school, and hold up the same banner plus some sort of reference to the supreme court walking us towards Orwell's 1984.
The school had nothing at all to do with the kid's activities at the time, and this is no different than (for example) the state revoking your drivers license because you put up a sign in your front door saying "vote for proposition xxx" or listening to that song "I can't drive 55" on the radio.
As it is, I'll just wait patiently for "the day they hung the lawyers".