The question of how to handle 404 pages and DNS redirects for things like mistyped URLs is becoming an increasingly important one. For some time, some web developers have been creating their own custom 404 pages in an effort to offer useful tools and navigation links instead of just an ugly dead end. But approaches to these problems from Google and Verizon—some of which can actually make revenue from mistyped URLs—are being met with mixed criticism and refreshed concerns over security and network neutrality.

Of mistyped URLs...

Last year, Verizon began redirecting mistyped URLs from its FiOS customers to its own custom search pages—complete with advertisements—regardless of what a user's default search settings. This feature, which Verizon calls "Advanced Web Search," requires the company to silently alter users' DNS. Consumer Affairs notes that Verizon allows users to opt out, but the company has still rolled it out to customers in the Midwest, Maryland, and Virginia.

While redirecting DNS for the purpose of making the best out of misspelled URLs may seem harmlessly appealing at face value, some are concerned over the functional and security risks involved. Back in 2004, ICANN smacked down VeriSign's SiteFinder service, which redirected requests for unregistered domains to an ad-heavy search page. Ars Technica spoke with Tim Wu, a Columbia Law School professor and network neutrality advocate, who has mixed feelings about Verizon's DNS redirecting. "I generally have no problem with good faith efforts by ISPs to help their customers," Wu told Ars. "It's when they try and manipulate the system that I am troubled. For example, obviously, if you typed in www.google.com and arrived at Verizon’s web site, I think you could hardly be happy with that."

Those concerned about this feature, however, are worried about the manipulation Wu mentioned. If Verizon is righteously redirecting in the name of bad spelling now, what's to stop it from beginning to bend the rules and alter search results or quietly insert its own affiliate ads into web sites? DNS redirects have also been known to cause problems with personal security software and custom DNS settings. The fact that this feature was automatically switched on is unfortunate in these cases, Verizon does allow customers to opt out of the service.

...and 404 redirects

Google has also ventured into questionably helpful territory by introducing similar mistyped domain and 404 page redirects into its Google Toolbar product. Available only in the version 5 beta for Internet Explorer for now, Google introduced a new feature that subverts 404 file not found errors with its own mixed solution. Some mistyped URLs, such as microsofft.com, will yield a simplified Google 404 error with a suggested URL and a search box, while others, like aple.com, will redirect to a full Google search.

Typing in nonexistent subdirectories at various sites leads to mixed results. Some end in a standard 404 error, while others present the redirected Google warning and search box. When news of this broke, some feared that Google would be trumping custom 404 pages with this toolbar by displaying its own redirected search tools and advertisements, but our testing reveals that the company treads carefully. It appears that any sites with custom 404 pages that present helpful navigation links or even simple warnings are left untouched by the Google Toolbar beta.

Ultimately, neither of these companies are showing irrefutable evidence of acting maliciously to alter search results or cause harm to the workings of the Internet. Both companies will argue that they are providing a service to customers who mistype URLs and may not be able to find what they're looking for. Critics of automatic redirection will counter that the likes of Verizon and Google are offering (and profiting from) solutions in search of a problem.