Site Categorization in Dell SonicWALL Content Filtering Service

Dell, through the SonicWALL acquisition, has been in the internet content filtering business for over a decade.  During that time the world has gone from fewer than a 100,000 registered URLs to more than a billion.  Our job is to categorize those sites and give IT administrators control over their network. In those 10 years, we’ve had very few complaints.  Yes, we sometimes rate a site in one way and either that site’s emphasis changes over time, or, we may make a categorization mistake.  It does happen.  In other cases a website generates little traffic and we don’t come across it so our system responds as “Not Rated".  On the whole though, we’ve been very good and we’ve received a lot of positive credit for it.  

Over the last few days, we’ve had a different experience.

A school had a policy to block a category of sites rated as Politics/Advocacy Groups at their site using our content filtering product. It’s important to note that our product does not come with that category turned on. The school actively turned it on. The result was a student was prevented from doing some key research. Further, the policy at this school allowed “Not Rated” sites to be accessed. Most school IT administrators block the Not Rated category since millions of new *** and malware sites come online each month and it is very important to block them until they can be rated. The combination of blocking Politics/Advocacy Groups had a bad outcome. The student found he was blocked from many conservative political sites but could get to many sites he described as liberal that had the category of “Not Rated.” The student couldn't do appropriate research and the combination of the block/allow policy lead to a perception that we had a political bias. Not only that, someone jumped to the conclusion that we somehow rated conservative sites and somehow gave liberal sites a “Not Rated” category. 

Amusingly, logic should have dictated a different conclusion. “If” we had somehow deliberately rated liberal sites “Not Rated” through some conspiracy, then it would mean more liberal sites would generally be blocked than conservative sites. Why? Because most IT Administrators naturally block the Not Rated category due to the dangers of exposing networks to malware and other problems. Kind of funny. If this conspiracy were true, it would actually be more anti-liberal in most networks. But guess what? This has become a run-away story.  

I was asked how we can filter conservative, liberal or other political categories. Here is what gets rated and how:

  • The ratings categories in the Dell SonicWALL Content Filtering Service do not have the granularity to block access based on conservative, liberal or any other political bias.  We provide a higher level category that blocks all “Political and Advocacy Groups” that does not take into account any political affiliation.  This category is not turned on by default.  A user must actively choose to turn it on.  The category is not able to single out any party bias.
  • An automated numerical frequency algorithm is used to determine the order of the queue for previously unrated sites.  Sites that receive the highest traffic are placed at the top of the queue, and conversely sites that have low traffic volume are lower in the queue.
  • We also provide users with a tool to assess how any particular URL is rated.  If a user finds a site that is not rated or is improperly rated, he or she can enter that URL into the tool and it goes for immediate review and rises to the top of the queue regardless of frequency.   There is no “selection” criteria used to determine what gets rated other than numerical frequency, or end user requests/submissions. 
  • The Dell SonicWALL Content Filtering Service allows administrators to block any site that has not been rated by providing a category called “Not Rated”.  It is important to note that Not Rated means that we have not yet had the opportunity to rate the URL.  It does not mean that we have reviewed the site and decided to rate it “Not Rated”.   Many organizations block the “Not Rated” category since millions of new URLs are introduced monthly and will not make it into the rating queue until there is sufficient traffic or an end user submits the site for rating. Not Rated should be blocked since millions of new malware sites appear monthly.

This is a tricky business and it is not a perfect science. But we do our best to help IT administrators by providing the tools so that they can use their networks the way they want to.  We don’t make any judgments, we simply try to give tools.  And if we make mistakes, we correct them. But, unfortunately, the subject area is not so exciting that it can support a full-blown conspiracy.

Illustration of how a content filtering client works

About the Author: Patrick Sweeney