ComputerWorld listed ad blocking extensions to Firefox in page two of its article “Top 10 Firefox extensions to avoid” specifically because ComputerWorld is an ad-supported publication. The author even goes so far as to say as much in the article. Call me an anti-capitalist, but I am bombarded with enough advertisements when I open a newspaper, magazine or even the refrigerator. I long for those halcyon days of yore when the Internet was a place to get information without being bombarded by pop-ups and banner ads.
And the situation has not gotten any better over time. As web technology advances, so do the ways in which advertisers try to grab our attention. ComputerWorld specifically uses one sort of ad that I find most annoying. When you move your mouse over the ad to get to a link in the article, the banner ad increases to four times its original size blocking the article that you are reading. You then have to click on the close link embedded in the ad (therefore tracking your interaction with it) in order to get back to the article. But be careful! If you accidentally touch the ad again with your mouse, it pops right back up.
Most recently, the media has picked up on the story of advertisers marketing to children over the internet. [see here] I find it ironic that the largest advertising medium is complaining about advertisements directed at children. Have you watched Saturday morning programming lately? Perhaps the complaint is that it is cutting into their market share.
I am convinced that I am not alone in my ire toward mass advertisement. The number of commercial software products out there to stop pop-ups, pop-unders and banner ads is continually increasing. Most of them advertise in much the same way as the ads they claim to prevent.
Current browser technologies even come with their own pop-up blocker settings, although Microsoft specifically requires the feature to be turned off to access many of the features of their sites and products. Why? One possibility is that Microsoft has extended its portfolio by buying two large internet advertising firms including its largest acquisition to date – aQuantive. This is the second major advertising purchase made by Microsoft in a month, the first being ScreenTonic. The CEO of Microsoft makes their love for internet advertising clear. “Really understanding the power of advertising as an Internet business model we came to later than I wish we had. That's the No. 1 thing I regret.” [see here]
So, what can be done to limit the number of advertisements that internet users are subjected to? What is the most cost effective way of shielding our children and ourselves from the constant barrage of adware, spyware and trojans?
AdBlock, AdBlock Plus and Filterset.G
These free Extensions for Mozilla Firefox go a long way toward reducing the number of ads that are displayed in your browser. Most superfluous elements are tagged with a small file-folder-type tab. Users can click on the tab and opt to block the ad at its source. Not only does this block the ad from the current page being viewed, it blocks the ad from any subsequent pages on any other site as well. By using wildcards, you can select to block all ads from a given ad provider such as doubleclick.net. AdBlock is open-source which means you are free to use it wherever you wish.
An additional extension for Firefox is Filterset.G which allows you to automatically download a shared list of internet advertisers so that these sites are blocked without your having to manually add each advertiser. It requires the installation of AdBlock in order to function. The software updates its list every four to seven days to keep you current on advertisers without overloading the database servers. Filterset.G is not open-source; the filters are only free for personal, non-commercial use, and redistribution of it is not permitted.
[Edit: On January 12, 2018 I received an email concerning this elevel-year-old post informing me that Fitlerset.G is no longer available and is a broken link. The sender suggested that I instead post a link to https://digital.com/blog/webextensions-firefox/. I have not checked this link for authenticity. It may be a commercial link, or it may not. Click at your own risk. As this post was 11 years old, it would be too time consuming to investigate accuracy of a 2007 post to ensure 2018 technology still applies.]
Modified HOSTS File
Understanding how internet traffic works is essential in determining ways to mitigate the behavior of your computer on the net. When you enter a URL such as www.antimidas.net into your browser and click Go, you set off a chain of events. Computers are addressed by numbers and only referenced by names. Think of it as an over-glorified telephone switching network. You don’t look people up in a phone book by number. You look for them by name because it names are easier to remember than numbers. Computers function in the same manner.
Your computer first looks at a file on your computer called HOSTS to see if it can find out what IP address is associated with the requested site. This is like a little black book. If it does not find an entry, it searches for local DNS servers – similar to the yellow pages you store under your coffee table. If it still cannot find the number, it forwards the request to your ISP or an outside DNS service in order to locate the appropriate entry – the equivalent of calling information for the number without the added cost.
The fastest way to block a website is to modify the little black book. You effective provide your browser with a wrong number rather than no number so that it stops looking anywhere else for the information. One such list that I use can be found here. The site provides instructions for locating and replacing the file on your computer. This is a completely manual process. You will need to revisit the site periodically to download any updated HOSTS file and replace the old one. As a general rule, I only do this when I notice an increase in the number of ads getting through.
The list is comprehensive. The creators not only index known ad providers. They also have added entries to prevent most known trojans and spyware from being installed on your computer. It is well worth the effort.
You will notice that the file refers all of the ad sites to an IP address of 127.0.0.1. This refers back to your local machine. If you have the knowhow, you can install a web server on your local machine and put a blank page on it so that all blocked ads simply appear as whitespace. I have mine on a separate server, so I changed every occurrence of the loopback IP address to the IP of the server hosting the page. It is important to keep the first entry of 127.0.0.1 localhost intact.
The second place where sites can be blocked is at the local DNS server. Since home users generally do not have a DNS server on their network, they can skip reading this part. If you have a DNS server, you would know it because you would have had to configure it yourself or you are the network administrator for your company. For the purposes of this article, I am going to assume that you are running Microsoft Windows Server 2000 or greater to provide internal DNS to your local network.
Microsoft’s DNS service is generally considered to be dynamic because it constantly updates its cache with new sites. It conforms to the BIND standards and is easy to modify and manage. For this exercise, we will be adding zones to intercept requests from the network for resources at an undesired site.
In your DNS tool, expand your DNS server and the Forward Lookup Zones item. I already have several forward lookup zones added. While I have used forward lookup zones to block ad sites, most of these are configurations to prevent access to specific sites by employees attached to my network. Let’s take a look at both situations.
If you have a problem with too many users accessing a particular non-work-related site such as YouTube, you can create a new zone called youtube.com by right clicking on the Forward Lookup Zones heading. Once the zone is created, you can add a new host (A) record to it. This (A) record can contain either the name of the specific server to block (such as www) or it can contain a wildcard * which will affect all sites within that domain. Generally, you would enter the IP address of a server hosting a blank page to keep this behavior transparent. But you could also have fun and put in the IP address of your primary business application to remind users that they should be doing their jobs rather than playing on company time.
The most useful thing to note is the top entry for adservers. Wolfram Kraushaar has provided instructions here for how to configure your DNS server to utilize its cache to block ad servers. It is worth checking out, but will still require manual updating of the registry on your server to stay current. I have this as a failsafe on the rare chance that one of my users gets smart enough to delete their HOSTS file and restore it to the default.
A little higher up on the scale is the use of proxy servers. A proxy server works by acting as a middleman for any internet requests. It will then generally cache the page so that future lookups by other users will be served the page from the cache rather than causing a new copy of the page to be downloaded. This has the added functionality of reducing your bandwidth utilization caused by frequent visits by multiple users to static pages. The proxy server does a simple query to ensure that the data in its cache is current before determining whether to download a new version of the page or to provide the user with a cached copy.
In addition to the normal functioning of the proxy server as described above, you can usually configure filters to allow access to certain sites while prohibiting others. You can either do this en masse for all users, or limit freedom to only a subset of users on your network. A list of open source proxy servers is available here . You can also opt to use commercial software such as Microsoft Internet Security and Acceleration (ISA) server. Some products such as ISA Server double as comprehensive firewall solutions. You usually get what you pay for.
Outside of all of the ways in which you can intercept and block traffic during the DNS validation or with the components prebuilt into your web browser of choice, a variety of commercial and free pop-up blockers are available on the net. The methods above are effective at reducing the number of pop-ups because they block access to the ads that cause them. But there are others that you can use.
One of the best choices for free pop-up blocking is the Google Toolbar. It is proficient and allowing you to switch between allow and deny modes while providing a host of other features. But keep in mind that Google has purchased DoubleClick which is known for collecting as much information about people and their web habits as is possible. It has the potential for being a spyware clearinghouse. In fact, I block access to all known DoubleClick sites to prevent their invasive tracking behavior.