Rogers also used to serve ads in place of an error message when a bad URL was requested. That was the final straw causing me to cancel my service with them and switch to Teksavvy.
That was reason #2. Going from a 60gb cap (which I'd often go over by about 20gb) to a 300gb cap actually saved me a lot of money because of overage charges.
I believe Comcast hijacked NXDOMAIN DNS replies and replaced them with their own IP address, causing every non-existant domain name to go to their search page you had to opt-out of.
Afaik, Airtel still does it and people still put up with it. I think they do the usage % notification hijacking as well without understanding even a bit that that internet is a pipe and people use applications other than web browsers and protocols other than http.
Yea I was not sure. I left them after their data cap for "high speed" "unlimited" internet cap was 3 gb per month. I can put up with js injection but ridiculous data caps are something I can't live with.
I'm pretty sure you can forcefully opt out by using a DNS server that isn't run by scumbags, like 8.8.8.8 and 8.8.4.4 for Google Public DNS. I hear OpenDNS is similarly good.
OpenDNS does the same thing these people are complaining about -- they wrap the missing domain in something like a search page that has their logo and custom ads on it.
Originally I wrote a GreaseMonkey script to redirect me from their ad page to a Google search. At the time, it was better than nothing, but still not enough to keep me from dropping Rogers. YMMV, Last updated 2008: http://userscripts.org/scripts/show/30326
