The government’s interest in preventing the dissemination of obscenity, child pornography, or, in the case of minors, material harmful to minors, is well-established.  Speech that is obscene, under the legal definition of obscenity set forth in the margin, is unprotected under the First Amendment, and accordingly the state has a compelling interest in preventing its distribution.  See Miller v.  California, 413 U.S. 15, 18 (1973) ("This Court has recognized that the States have a legitimate interest in prohibiting dissemination or exhibition of obscene material."); Stanley v.  Georgia, 394 U.S. 557, 563 (1969) ("[T]he First and Fourteenth Amendments recognize a valid governmental interest in dealing with the problem of obscenity."); Roth v.  United States, 354 U.S. 476, 485 (1957) ("We hold that obscenity is not within the area of constitutionally protected speech of press.").  The First Amendment also permits the state to prohibit the distribution to minors of material that, while not obscene with respect to adults, is obscene with respect to minors.  See Ginsberg v.  New York, 390 U.S. 629, 637 (1968) (holding that it is constitutionally permissible “to accord minors under 17 a more restricted right than that assured to adults to judge and determine for themselves what sex material they may read or see").  Proscribing the distribution of such material to minors is constitutionally justified by the government’s well-recognized interest in safeguarding minors’ well-being.  See Reno v.  ACLU, 521 U.S. 844, 869-70 (1997) ("[T]here is a compelling interest in protecting the physical and psychological well-being of minors which extend[s] to shielding them from indecent messages that are not obscene by adult standards . . . .”) (internal quotation marks and citation omitted); New York v.  Ferber, 458 U.S. 747, 756-57 (1982) ("It is evident beyond the need for elaboration that a State’s interest in safeguarding the physical and psychological well-being of a minor is compelling.”) (internal quotation marks and citation omitted); Ginsberg, 390 U.S. at 640 ("The State . . . has an independent interest in the well-being of its youth.").

The government’s compelling interest in protecting the well-being of its youth justifies laws that criminalize not only the distribution to minors of material that is harmful to minors, but also the possession and distribution of child pornography.  See Osborne v.  Ohio, 495 U.S. 103, 111 (1990) (holding that a state “may constitutionally proscribe the possession and viewing of child pornography"); Ferber, 458 U.S. at 757, 763 (noting that “[t]he prevention of sexual exploitation and abuse of children constitutes a government objective of surpassing importance,” and holding that “child pornography [is] a category of material outside the protection of the First Amendment").  Thus, a public library’s use of software filters survives strict scrutiny if it is narrowly tailored to further the state’s well-recognized interest