Content-Filtering Tools: An FAQ for Nonprofits

Advice to help you choose software or hardware for your computer lab

By: Brian Satterfield

June 5, 2007

Organizations that operate public computer labs may consider restricting users' access to certain types of online content for a variety of reasons. Some may do so for financial or legal motives: If you work for a library or school and want to receive federal funds to purchase technology equipment, for example, you are required by a federal law called the Children's Internet Protection Act (CIPA) to implement a content-filtering solution.

Other organizations, meanwhile, may choose to filter content for more practical reasons. If your nonprofit is starting an after-school technology education program for sixth graders, for instance, you may simply want to prevent your students from accessing online content that their parents might object to.

Yet regardless of your motivations for filtering content, you will have a hard time getting the job done without content-filtering hardware or software. While not foolproof, content-filtering systems can save you the trouble of manually monitoring users' behavior by automatically preventing access to Web sites that display pornography, glorify gratuitous violence, or install malware.

To help your nonprofit, school, or library make informed decisions when choosing a content-filtering tool, we've compiled the answers to a few common questions about this technology. If you need more background on how content filters work and the issues surrounding them, read TechSoup's article Understanding Content Filtering: A General FAQ for Nonprofits.

1. What major features should I look for in a content-filtering solution?

Content-filtering systems restrict content based on frequently updated lists of Web sites that the product's manufacturer has deemed harmful or offensive. If a student tries to open a Web site on a filter's restricted list, for example, the filter will block his access to that site.

Many content-filtering systems, however, offer other features beyond simply blocking sites. Here are a few you may want to consider when researching a particular tool.

Password Protection

The ability to arm the content filter with an administrator password is a crucial feature, as this will prevent users from changing the filter's settings or disabling it altogether. While a password-protection feature is standard in most software-based filters, it's advisable to download a trial version of the filter (if available) to ensure that the program cannot be uninstalled without supplying a password.

In Windows operating systems (OS), you can uninstall most software by clicking Start > Settings > Control Panel > Add and Remove Programs, then looking for the program's name and clicking the Remove icon. If for some reason the application does not give you the option to uninstall it from the Control Panel, try exploring your computer's C drive, browsing to the Program Files folder, opening the application's folder, and clicking a file called "uninstaller.exe" or something similar. If the filter has strong security measures in place, it should prompt you to enter a password before you uninstall it.

Blacklists and Whitelists for Keywords and Sites

Because most content filters block material based on keywords and sites determined by the product's manufacturer, they can often either accidentally obstruct useful sites or allow access to objectionable sites that the manufacturer is not yet aware of. To give you greater control of what content can and cannot pass through the filter, many software and hardware vendors include blacklist and whitelist features that let administrators specify which sites should be blocked and which should be allowed.

A blacklist allows the filter's administrator to specifically block entire Web sites or particular Web pages by entering a URL; many filters also allow you to build a customized blacklist of keywords and block any pages containing those terms. Whitelists, on the other hand, serve the opposite purpose: They let you specify which URLs and keywords to allow. Some content filters will even let you blacklist and whitelist other software applications, helpful if your public computers serve users of different ages who need access to different programs.

Multiple User Profiles

If your library or organization lacks separate computer labs for adult and child patrons, you may have a mix of age groups using the machines at any given time. In such cases, running the same level of filtering on all of the computers might either expose children to inappropriate material or prevent adults from accessing content.

To help administrators tailor Web access for each set of users, many content filters allow you to set up separate logins to allow different levels of permissions. So while the adult user profile might allow access to all content except pornography, the profile for teenagers might also restrict access to sites that reference violence and illegal drugs.

Ability to Set Usage Time Limits

Although you may post signs or verbally remind patrons of time-usage limitations on your public computers, your staff may not always have the time to enforce this rule. If your users routinely fail to adhere to your use policy, look for a content filter that includes a time-management feature to ensure that all your patrons get time online.

A time-management feature lets the administrator specify how long per day or between which hours a user is allowed to access the Internet. Shortly before their session is set to expire, the user may receive notification that all Internet access is about to be suspended, although some filters might simply shut down the Web browser without notification.

Ability to Override the Filter

Content filtering is an imperfect technology, so at some point, a user will likely inform one of your staffers that the filter is blocking a site they legitimately need to access. Therefore, the ability to quickly bypass the filter for a particular site can be a helpful feature, saving your staff the time of having to change the filter's settings each time you get a request. Like the content filter itself, the override feature should be protected by a password that only the administrator knows.

User Notification

To help retain your patrons' trust, it's important to make sure that the content filter clearly discloses its presence each time it blocks an objectionable Web page by displaying a message. While most content filters will display a standard notification to users by default, others offer several notification choices or allow the administrator to create a custom message.

Session Reports

Many content filters also log a user's computer activities — including typed URLs and programs accessed — and provide the administrator with a detailed report. While you should take care to respect your patrons' privacy by erasing these logs at regular intervals, periodically checking the reports to see what sites the filter is actually blocking can help you make corrections and unblock sites that have been misconstrued as objectionable.

For more information on what features to look for in a content-filtering product, read WebJunction's article CIPA: Which Filtering Software to Use.

2. What factors should I consider when choosing among the different types of hardware and software-based filters?

Several factors — including the number of public computers in your lab, the amount of time your staff can dedicate to maintaining the filter, and your budget — will likely help you decide whether you want to investigate a centralized hardware or software solution or an application that you install on each machine.

Hardware-based content filters act as a barrier between the Internet and all the computers on your network, meaning that you can adjust the filtering settings for multiple computers from a central control panel and don't have to make changes on every single machine. Some hardware firewalls also include content-filtering functionality, so if your organization is considering buying a firewall, you might be able to save yourself some money down the road by purchasing a device that includes a filter.

(Note that despite their advantages, hardware-based filters can be relatively expensive for organizations on a tight budget, costing upwards of $1,000, not including additional subscription fees.)

If your organization already has a firewall and other necessary network hardware, but still has more than a handful of computers in its lab, you might want to look into a centralized software solution. Like hardware-based content filters, these types of applications provide filtering functionality to multiple computers on a network and can be adjusted from the administrator's machine. However, centralized software filters can also be pricey and some may carry a yearly subscription fee.

If you run a small lab with fewer than 10 computers, an expensive, centralized solution might be overkill. Alternatively, you could choose to purchase individual licenses for desktop filtering applications. Desktop filtering applications generally cost between $40 to $80 for one license (either as a one-time purchase or for an annual subscription fee) and can often be purchased at a discounted rate if you buy multiple licenses. Some desktop filters — such as K9 Web Protection and Naomi — can even be found for free.

However, note that if you choose to install desktop-based filters on your computers, your staff will have to manage the application on each computer, including unblocking useful sites, adding new keywords to the blacklist, and creating new user profiles.

3. Where can I find reviews or comparisons of hardware and software content filters?

Now that you know a bit more about software- and hardware-based content filters, you may be ready to start researching actual products to find one that best fits your needs.

Compiled by Lori Ayre — a professional library technology consultant and founder of the Galecia Group — LibraryFiltering.org's comparison chart lists more than 20 software- and hardware-based content filters, many of which are centralized solutions. The chart not only compares detailed aspects of the filtering technology used and administrative tools included, but also offers in-depth information on pricing and supported platforms.

If you're mainly interested in a software-based desktop solution, you might have a look at Top Ten Reviews' 2007 Internet Filter Report, which not only provides a feature-comparison chart of 10 filtering programs but also reviews for each product. Consumer Guide has also published reviews of 14 content-filter applications and rated products according to their ease of use, feature set, performance, and value.

4. Does my Web browser offer any content-filtering features I can use for free?

If you only need to restrict content on a couple of computers and don't need a lot of extra filtering or management features, you might want to experiment with Microsoft Internet Explorer's (IE) built-in content-filtering tool, called Content Advisor.

If your public computers have IE version 5 or later installed, you can access Content Advisor by clicking Start > Control Panel > Internet Options. From the pop-up window that appears, click Content, locate the Content Advisor pane, and click Enable. Another window will appear, allowing you to control the amount of nudity, sex, adult language, and violence your users see by moving sliders from left (least restrictive mode) to right (most restrictive mode). If you want to block or allow specific Web sites, you can do so by clicking the Approved Sites tab and entering URLs into the appropriate box.

Note that while users will not be able to change or disable IE's Content Advisor settings without an administrator password (if you've set your computer up to prompt for an administrator password when you change these settings), instructions for disabling this password are readily available online. Therefore, Content Advisor may be most effective when used in computer labs that primarily serve younger children.

Now that you know a bit more about what to consider when choosing a content filter, it's time to narrow your options down to a few choices and check them out firsthand. If you're interested in a software solution, you should more than likely be able to download a free trial version of the product. On the other hand, if a hardware-based product seems to better suit your needs better, contact the manufacturer and request a live demonstration. Either way, you're hopefully well on your way to finding a filter that will keep both you and your patrons happy and secure.

Copyright © 2007 CompuMentor. This work is published under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 License.