What types of web sites would you most like to block from appearing on your home or office computer?
OpenDNS, about which I've written here before, is a service that you can use as an alternative to your own Internet service provider's domain name server (DNS).
A DNS is like a big address book that translates the text-based web page or e-mail addresses we all use ( http://www.t-g.com , email@example.com, and so on) into the numerical IP addresses which are really used behind the scenes of the Internet (These are numbers separated by periods, such as 12.345.67.8).
Your ISP's domain name server probably works just fine most of the time, but when it's down, you can't do much (if anything) on the Internet until it gets fixed. If you have a mysterious Internet outage that fixes itself later, it may well be that your ISP's DNS wasn't working.
OpenDNS ( http://opendns.com ) claims to be faster and have fewer outages than your ISP's domain name server. It also is more pro-active than your ISP in catching misspellings of the most common web addresses and re-directing you to the proper address instead of the one you actually typed. That can be a safety measure, since some malicious sites choose names close to those of the most popular web sites in hopes of attracting accidental visitors.
You can use OpenDNS anonymously, just by changing the DNS setting within your operating system so that it points to the OpenDNS servers (126.96.36.199 and 188.8.131.52) instead of your ISP's servers.
Using the service anonymously is enough to give you the supposed speed and reliability benefits. But if you register with the web site, OpenDNS also gives you the power to block certain web addresses or types of web addresses -- for example, pornography sites or sites that are known to have malicious software -- from showing up on your computer.
No such blocking software is perfect, and new web sites are being created every day, making any sort of blacklist out of date almost as soon as it's created. But OpenDNS does as good a job as reasonably possible of keeping a list and giving you the power to block unwanted sites.
You can also tell OpenDNS to block specific sites, or to allow specific sites even if they're within a blocked category.
OpenDNS offers its basic service free to home users, but it makes money by selling advanced services to businesses, which can, for example, block individual sites from being used by employees while on the job.
The company also makes money by selling keyword-related ads on the error pages that it generates when you type something in your browser's address bar that isn't a valid web address.
OpenDNS recently released its annual report of the most-blocked categories and sites.
The most-blocked categories, in general:
The most-blocked sites (among all users):
The most-blocked sites (among business users only)
There's also a list of the most whitelisted sites. These are cases in which, even though a category has been blocked, the user decides to allow a particular site within that category:
The company noted that some of the same sites rank high on both the whitelist and the blacklists, which it says "may indicate the diverse perspectives people have regarding many of these sites."
--John I. Carney is city editor of the Times-Gazette and covers county government. He is also the author of the self-published novel "Soapstone." His personal web site is lakeneuron.com.