In a computer security sense it is an attack, because there are parties with conflicting goals and one party is trying to use technical means to stop another pa

In a computer security sense it is an attack, because there are parties with conflicting goals and one party is trying to use technical means to stop another party from achieving its goals. (The students can also be viewed as attackers by the network operator when they try to circumvent the blocking by disguising the nature of their communications.) It's true that it would be socially awkward to say to school officials that they are carrying out an "attack" against students.