Similar less restrictive alternatives exist for preventing minors from accessing material harmful to minors.  First, libraries may use the tap-on-the-shoulder method when minors are observed using the Internet to access material that is harmful to minors.  Requiring minors to use specific terminals, for example in a children’s room, that are in direct view of library staff will increase the likelihood that library staff will detect minors’ use of the Internet to access material harmful to minors.  Alternatively, public libraries could require minors to use blocking software only if they are unaccompanied by a parent, or only if their parent consents in advance to their child’s unfiltered use of the Internet.  “A court should not assume that a plausible, less restrictive alternative would be ineffective; and a court should not presume parents, given full information, will fail to act.”  Playboy, 529 U.S. at 824.  In contrast to the “harmful to minors” statute upheld in Ginsberg v.  New York, 390 U.S. 629 (1968), which permitted parents to determine whether to provide their children with access to material otherwise prohibited by the statute, CIPA, like the Communications Decency Act, which the Court invalidated in Reno, contains no exception for parental consent:  [W]e noted in Ginsberg that “the prohibition against sales to minors does not bar parents who so desire from purchasing the magazines for their children.”  Under the CDA, by contrast, neither the parents’ consent – nor even their participation – in the communication would avoid the application of the statute.

Reno, 521 U.S. at 865 (citation omitted); see also Ginsberg, 390 U.S. at 639 ("It is cardinal with us that the custody, care, and nurture of the child reside first in the parents, whose primary function and freedom include preparation for obligations the state can neither supply nor hinder.” (quoting Prince v.  Massachusetts, 321 U.S. 158, 166 (1944))).

The Court in Playboy acknowledged that although a regime of permitting parents voluntarily to block cable channels containing sexually explicit programming might not be a completely effective alternative to the challenged law, which effectively required cable operators to transmit sexually explicit programming only during particular hours, the challenged law itself was not completely effective in serving the government’s interest:  There can be little doubt, of course, that under a voluntary blocking regime, even with adequate notice, some children will be exposed to signal bleed; and we need not discount the possibility that a graphic image could have a negative impact on a young child.  It must be remembered, however, that children will be exposed to signal bleed under time channeling as well. . . .  The record is silent as to the comparative effectiveness of the two alternatives.