[swhipple]

Is this documented somewhere? I tried searching for a couple combinations of "linux mint dns ad injection", but couldn't find anything relevant.

[guelo]

I was referring to their use of OpenDNS http://forums.linuxmint.com/viewtopic.php?f=90&t=128529

And hijacking Google search on Firefox, http://blog.linuxmint.com/?p=142

[vertex-four]

OpenDNS hasn't done ad pages for non-existent domains in ages. As for "hijacking" Google search, that's simply setting a different default - you can change it and nothing tries to stop you, and OS upgrades won't change it back (I believe).