websites, bulletin boards, chatrooms, and email are potentially interactive.”  Seth F. Kreimer, Technologies of Protest:  Insurgent Social Movements and the First Amendment in the Era of the Internet, 150 U. Pa.  L. Rev. 119, 130 (2001). 
       We acknowledge that the Internet’s architecture is a
human creation, and is therefore subject to change.  The foregoing analysis of the unique speech-enhancing qualities of the Internet is limited to the Internet as currently constructed.  Indeed, the characteristics of the Internet that we believe render it uniquely suited to promote First Amendment values may change as the Internet’s architecture evolves.  See Lawrence Lessig, Reading the Constitution in Cyberspace, 45 Emory L.J. 869, 888 (1996) ("Cyberspace has no permanent nature, save the nature of a place of unlimited plasticity.  We don’t find cyberspace, we build it."); see also Lawrence Lessig, The Death of Cyberspace, 57 Wash. & Lee L. Rev. 337 (2000). 
       For First Amendment purposes, obscenity is “limited to
works which, taken as a whole, appeal to the prurient interest in sex, which portray sexual conduct in a patently offensive way, and which, taken as a whole, do not have serious literary, artistic, political, or scientific value.”  Miller v.  California, 413 U.S. 15, 24 (1973). 
       The Supreme Court in Reno explained: 

The District Court found that at the time of trial existing technology did not include any effective method for a sender to prevent minors from obtaining access to its communications on the Internet without also denying access to adults.  The Court found no effective way to determine the age of a user who is accessing material through e-mail, mail exploders, newsgroups, or chat rooms.  As a practical matter, the Court also found that it would be prohibitively expensive for noncommercial – as well as some commercial – speakers who have Web sites to verify that their users are adults.  These limitations must inevitably curtail a significant amount of adult communication on the Internet.

Reno, 521 U.S. at 876-77 (citation omitted). 
       To the extent that filtering software is effective in
identifying URLs of Web pages containing obscenity or child pornography, libraries may use filtering software as a tool for identifying URLs in their Internet use logs that fall within these categories, without requiring patrons to use filtering software.  As the study of Benjamin Edelman, an expert witness for the plaintiffs, demonstrates, it is possible to develop software that automatically tests a list of URLs, such as the list of URLs in a public library’s Internet use logs, to determine whether any of those URLs would be blocked by a particular software filter as falling within a particular category.  Alternatively, library staff can review the Internet use logs by hand, skimming the list of URLs for those that are likely to correspond to Web pages containing obscenity