registration information, and tens of thousands of Web sites contain child pornography. 

Libraries have reacted to this situation by utilizing a number of means designed to

insure that patrons avoid illegal (and unwanted) content while also enabling patrons to

find the content they desire.  Some libraries have trained patrons in how to use the

Internet while avoiding illegal content, or have directed their patrons to  preferred  Web

sites that librarians have reviewed.  Other libraries have utilized such devices as recessing

the computer monitors, installing privacy screens, and monitoring implemented by a  tap

on the shoulder  of patrons perceived to be offending library policy.  Still others, viewing

the foregoing approaches as inadequate or uncomfortable (some librarians do not wish to

confront patrons), have purchased commercially available software that blocks certain

categories of material deemed by the library board as unsuitable for use in their facilities. 

Indeed, 7% of American public libraries use blocking software for adults.  Although such

programs are somewhat effective in blocking large quantities of pornography, they are

blunt instruments that not only  underblock,  i.e., fail to block access to substantial

amounts of content that the library boards wish to exclude, but also, central to this

litigation,  overblock,  i.e., block access to large quantities of material that library boards

do not wish to exclude and that is constitutionally protected. 

Most of the libraries that use filtering software seek to block sexually explicit

speech.  While most libraries include in their physical collection copies of volumes such

as 

The Joy of Sex

 and 

The Joy of Gay Sex

, which contain quite explicit photographs and

descriptions, filtering software blocks large quantities of other, comparable information

5