That's the failure in that logic. "Purely from a security viewpoint," it would make sense to strip all airline passengers naked and force them to stow all their luggage/clothes (i.e. no carry-ons), and have armed security agents staring them down the entire flight.
Hmmm, that brings up the question "Can this software ever be moral or legal?"
I.e. if you were to use it outside of the context of a school, there's still the possibility a minor might steal your laptop, set it up in his bedroom, have legal (for him and her) XXX with another minor....
In the above case I think you haven't broken the spirit of US child porn laws (that they are born illegal because they can't be taken without hurting the minor(s) in question), but I could be wrong. Legally your case is much iffier. Morally it's stronger, but how much so?
That's the failure in that logic. "Purely from a security viewpoint," it would make sense to strip all airline passengers naked and force them to stow all their luggage/clothes (i.e. no carry-ons), and have armed security agents staring them down the entire flight.