What I disagree with is what he does with this maxim, which is translate it into:
"Protecting Children is not Censorship"
While protecting children is a laudable goal, it is not a "get out of jail free card." One could take many kinds actions to protect children. Some might operate well within Free Speech or other basic civil liberties, but some might not. If this is difficult to see in terms of Free Speech, try thinking about it in terms of a more tangible civil liberty, such as the Second Amendment's guarantee of the Right to Bear Arms. Would it protect children if we were to confiscate all firearms now in private hands? Clearly it would, since children all too often are injured or killed in the crossfire of misused guns. Would it be legal to implement such a confiscation? Clearly it would not, since the Second Amendment forbids it, regardless of goals or motivation. Neither would it be legal to attempt to reduce all adults to reading only books that are fit for children, since the First Amendment forbids it, regardless of goals or motivation. Simply stated, the ends do not justify the means.
To be fair, SafeLibraries often appends the word "legally" to the front of his maxim:
This, of course, is a mere tautology, an exercise in circular logic that says nothing, since censorship itself is illegal (that is, the conclusion is embedded in one of the premises).
"Legally protecting children is not censorship"
SafeLibraries counts a wider variety of actions as "legally protecting children" than courts would ever allow. This arises from his abuse of the concept of the "compelling state interest." The compelling state interest provides a motivation for enacting laws to protect children, but it doesn't make any and all such laws acceptable under the First Amendment. When courts talk about this compelling state interest in terms of the kinds of laws that can actually be enacted -- as opposed to just as a motivating principle -- they always attach two conditions. SafeLibraries is ignoring those conditions.
What the courts say, more completely than SafeLibraries tends to admit, is:
The state can restrict access to protected speech
IF there is a compelling state interest
AND the law is narrowly tailored to achieve that interest
AND the law is the least restrictive alternative available.
When you respect the constraints that the "ands" impose on the "if," you get restrictions on Free Speech that are limited enough that the courts might permit them. If you ignore the constraints, you get a law that is overly broad, and will be overturned by the courts, as they have done time and again.
SafeLibraries' censorious rhetoric suffers from "mission creep," a process by which a reasonable goal gets expanded and expanded until it becomes unworkable and unachievable. It is not enough for him that material that meets the current definition of obscenity can easily be prohibited under existing law. It might be enough for him -- I don't know -- to add some restrictions on material that is not obscene for adults but is too sexually explicit for children. Such a goal might be achievable, but he'll never achieve it. He undermines his own efforts by overreaching. He ignores the need for narrow tailoring and minimal restrictions, and so supports restrictions no court will stand for. He tries to use the goal of protecting children as a "get out of jail free" card. He tries to make the ends justify the means.
If we really want to protect children, shouldn't that include protecting the Free Speech rights that even minors have in our legal system? If we are overzealous in attempts to protect children from certain harms, and in the process trample those rights, have we not become a source of harm to the very children we are trying to protect?