My rather large ISP, Charter, has been redirecting not found domains requested from a browser to a query on 'searchassist.teoma.com' for a few years. Very annoying; I block it in my hosts file.
Last I checked, Charter blocks outgoing DNS to servers other than theirs. Based on searching around, it sounds like they go back on forth on that policy.
Perhaps it varies by area? I'm in Wisconsin and I've been using 8.8.8.8 and/or 8.8.4.4 since I started getting service from Charter about a year ago, and I've never had a problem with it. Of course, doing that means I never noticed that they hijack NXDOMAINs, which definitely drops them a few notches in my eyes. I've had other ISPs do that to me; it's kind of infuriating.
