This is pretty blatant:

Rogers, a huge cable internet provider in Canada, has decided to hijack all unregistered domains, and replace them with Yahoo! advertisements. This means Rogers users who type in a domain that doesn’t exist, are now getting Yahoo ads instead of the normal “not found” error.

Interestingly, Rogers also decided to do this with subdomains. So for example, example.google.com now takes you to the following advertising:

— Rogers Hijacks Domain Name System, Puts Yahoo! Ads on Google’s Subdomains, John, Blamcast, 20 July 2008

The author points out that this essentially the same thing Verisign did in 2003 until they stopped due to massive backlash.

-jsq