Took the sarcasm out of this...
IF the .gov wants to effectively strip your right to defense THEN they are responsible for your defense.
Oh wait...
Warren v District of Columbia
Nevermind...sarcasm back on!
But in the case you link above it was that "the gov does not need to protect an individual just society" thus why I say form a class-action lawsuit and say that the entire school population (students, faculty, admin) was in danger and the city/state/fed failed to protect society (as a whole).