I just noticed Cablevision’s Optimum Online service has begun hijacking DNS Error pages with, you guessed it, ad-sponsored results:

And apparently I’m not the only one that noticed: Justin Flood and Dan. As Justin Flood reported Cablevision has secretly adjusted their TOS to reflect this morally questionable service:

The preceding search results page is displayed to you as a result of the specific Domain Name Service (DNS) servers used by Optimum Online to look up domain names. If you misspell or mistype a web address, dead-end “no such name” errors can occur. However, the DNS servers used by Optimum Online are designed to eliminate dead-end “no such name” error pages you can encounter as you surf the web. By displaying the preceding search results page, users know that the web site they’ve attempted to navigate to does not exist, and are presented with suggested sites they may have been seeking. No software is installed on your computer for this search service to work.

Don’t they realize the dangers of replacing DNS errors with content pages? Aside from hurting the underlying stability of the Internet, there have been instances where hackers have used such tools against customers. I know Road Runner customers have had to deal with this for a couple months now, although at least they have an outlet to turn it off. I did find this broken disable button on the “About This Page” link:

Upon clicking it, you see a message “You have successfully opted out of the DNS Assistance service” although it appears to be broken as the service is still in effect. Defective by design perhaps? Rolling out morally ambiguous feature with a broken disable link? Sounds like the same people that send spam messages to me.

Update: From user comments it seems clear most (soon to be all?) ISPs are doing the same. I’m just surprised after the fiasco with VeriSign, this issue has been ignored so often in the IT community. I guess better to better to have a choice which ISP hijacks your URLs?

Another Update: Maybe I’m the only one who’s having trouble opting out. Or perhaps I need to restart my router. Either way its definitely not working on multiple browsers and computers.