may not be used to access illegal speech.  Libraries may then impose penalties on patrons who violate these policies, ranging from a warning to notification of law enforcement, in the appropriate case.  Less restrictive alternatives to filtering that further libraries’ interest in preventing minors from exposure to visual depictions that are harmful to minors include requiring parental consent to or presence during unfiltered access, or restricting minors’ unfiltered access to terminals within view of library staff.  Finally, optional filtering, privacy screens, recessed monitors, and placement of unfiltered Internet terminals outside of sight-lines provide less restrictive alternatives for libraries to prevent patrons from being unwillingly exposed to sexually explicit content on the Internet.  In an effort to avoid the potentially fatal legal implications of the overblocking problem, the government falls back on the ability of the libraries, under CIPA’s disabling provisions, see CIPA Sec. 1712 (codified at 20 U.S.C.  Sec. 9134(f)(3)), CIPA Sec.1721(b) (codified at 47 U.S.C.  Sec. 254(h)(6)(D)), to unblock a site that is patently proper yet improperly blocked.  The evidence reflects that libraries can and do unblock the filters when a patron so requests.  But it also reflects that requiring library patrons to ask for a Web site to be unblocked will deter many patrons because they are embarrassed, or desire to protect their privacy or remain anonymous.  Moreover, the unblocking may take days, and may be unavailable, especially in branch libraries, which are often less well staffed than main libraries.  Accordingly, CIPA’s disabling provisions do not cure the constitutional deficiencies in public libraries’ use of Internet filters.

Under these circumstances we are constrained to conclude that the library plaintiffs must prevail in their contention that CIPA requires them to violate the First Amendment rights of their patrons, and accordingly is facially invalid, even under the standard urged on us by the government, which would permit us to facially invalidate CIPA only if it is impossible for a single public library to comply with CIPA’s conditions without violating the First Amendment.  In view of the limitations inherent in the filtering technology mandated by CIPA, any public library that adheres to CIPA’s conditions will necessarily restrict patrons’ access to a substantial amount of protected speech, in violation of the First Amendment.  Given this conclusion, we need not reach plaintiffs’ arguments that CIPA effects a prior restraint on speech and is unconstitutionally vague.  Nor do we decide their cognate unconstitutional conditions theory, though for reasons explained infra at note 36, we discuss the issues raised by that claim at some length.  For these reasons, we will enter an Order declaring Sections 1712(a)(2) and 1721(b) of the Children’s Internet Protection Act, codified at 20 U.S.C.  Sec. 9134(f) and 47 U.S.C.  Sec. 254(h)(6), respectively,