Blocking & Filtering

"Any content-based regulation of the Internet, no matter how benign the purpose, could burn the global village to roast the pig."

U.S. Supreme Court majority decision, Reno v. ACLU (June 26, 1997)

Blocking and filtering software for the Internet is one of the most hotly debated topics regarding free speech and the Internet. Many have criticized blocking software for being both under and over inclusive, and others have argued that blocking software should not be used at all in public institutions such as libraries and schools. On the other side, supporters of blocking software claim that is a legitimate method to regulate access to "inappropriate" material on the Internet, especially access for minors. But, before we begin to look at these debates directly, we have to examine how the different types of blocking software available work.

Nearly all blocking software contains several features that enable the user to customize it for their particular preferences. Users can set the particular levels and/or categories they want the software to screen. So, for example, a user could instruct his browser to block all nudity and sex acts, but still allow sex education and intolerance, while another users could do the opposite. Another common feature is the ability to unblock particular web sites when they are blocked. So, if a user was attempting to access the CNN web site, and it was blocked because it contained, for example, the Starr report, the user could unblock it. A final common feature of most blocking software is that it can be turned on and off for particular users on a particular machine, so that parents can turn the software on when their children are using the computer, but allow themselves unlimited access.

Blocking software works in several major ways: blocking by word, blocking particular sites, blocking all sites except those on a "white list," and blocking by preset ratings.

Most of the first blocking software worked by blocking words; the software would scan web sites for certain, unacceptable words such as "breast" or "sex." This type of software was often ridiculed, because it is ridiculously over broad, for example blocking sites on breast cancer or news sites about the President. In addition, this type of blocking has the disadvantage of not being able to scan pictures for unacceptable material.

A second type of stand-alone software blocks all material except that on an approved list. Obviously, this type of software is very effective in blocking unwanted material, but it also blocks an enormous amount of acceptable material.

A third type of blocking software blocks only those sites on its "black list" of unacceptable locations. In order for this to work, a software company hires people to scan the web for unacceptable sites and place them on the blocked list. While this is currently the most popular type of stand-alone blocking software used, it does have some problems. First, the user must trust the software company's determination about which sites are acceptable and which are not. Typically, software companies consider their list of blocked sites to be proprietary information and will not release it. In addition, certain software may use different definitions for what is unacceptable than the user.

For example, some software companies will block sites containing pro-homosexual positions, while others will ban the sites of conservative Christian groups for "intolerance". In addition, since the Internet expands and changes so rapidly that the lists cannot possibly keep up with all of the unacceptable material available. The lists cannot help but be under inclusive.

Platform for Internet Content Selection, or PICS, filtering on the web works substantially differently from the previously described types of software. This type of blocking relies on labeling of web sites by the sites' publishers, a third-party labeling service, or the user.

The technical specifications for this type of blocking were established by PICS, which, while not mandated by law, has quickly become the de facto standard for Internet rating systems. Building on the PICS platform are three major rating services: Net Shepherd, RSACi (the Recreation Software Advisory Council standard for the Internet) and SafeSurf. Each of these services provides a list of standards by which a site can be rated. The specific categories and levels that each provides are slightly different, but the basic categories include sex, violence, language, and nudity. A person simply fills out a form describing what levels of these and other categories appear on the site, and the rating is complete.

In addition, the PICS standard allows for third parties to rate any content on the Internet and make their ratings available. Using this feature, for example, a group opposed to internet pornography could then rate various sites on the web that refused to rate themselves, so that blocking software could still scan them.

Once this rating is complete, a user must have software that can read the labels to determine which sites are let by and which are blocked. The latest versions of both Netscape Navigator and Microsoft's Internet Explorer, the two major web browsers, have this capability. Furthermore, Net Shepherd has joined with Alta Vista, a popular Internet search engine, to provide the capability to limit search results to only those sites rated as acceptable to children.

A further important feature of PICS-based blocking is that they typically block all un rated sites as well as the sites on which the ratings do meet the appropriate standard set by the user.

Blocking software is available to users in several different formats. The first is stand-alone software. Several software manufacturers offer blocking software that can be installed on a personal computer or a server in order to block access to certain portions of the internet on that computer or server. This software is independent of the web browser or other program used to access the Internet, but works in conjunction with it. Some popular examples of this software include Cybersitter, X-Stop, Cyber Patrol, and SurfWatch.