Fine; re-phrase my question as "an organisation currently enjoying common carrier status."
That would not include any ISP in the United States. (Dunno about Canada.) As other people have pointed out, telcos are common carriers, ISPs aren't, not even ISPs that are subsidiaries of telcos. The legal status of ISPs in the U.S. can best be described as complicated. The DMCA provides limited immunity from copyright suits, and the CDA (47 USC 230) provides fairly broad immunity from some other kinds of suits. The U.S. is a common law country where you don't really know how a law will be applied until there are enough reported cases to establish persuasive case law, and we're a long way from that. So go ahead and run Tor if you want, but if the cops knock on the door, I would advise against saying "we're a common carrier so go away." R's, John