Qwest.net has become the second major North American ISP to block Internet Access to infected computers. http://blogs.pcmag.com/securitywatch/2007/10/qwest_takes_action_against_inf.php#comments   Cogeco Cable of Ontario, Canada has been doing this successfully for a while already.   Of note is that many ISPs are now throttling speeds for users of large file-sharing networks also. Comcast is of note here … More ISP’s blocking access to Internet