My 4 words do not suggest that every private entity in the U.S. is regulated directly by the USG, though you'd be hard pressed to find one that isn't. Perhaps the tobacco industry...|
ICANN has been billed as a unique public-private entity. It is not private, and it is regulated by the USG (tell me it isn't at the end of this month). If the USG wanted a truly private entity it could have put it up for competitive bids (mindful that they might have had problems with doing that with a public resource), and handed the root over to a private entity. It hasn't.
My 4 words also suggest nothing about whether the USG should take a more direct and central role in regulating ICANN, including the contracts it enters into - such as with registrars. Though seeing as you bring it up, I do think that if ICANN claims to accredit registrars it should be clearer with the public (or at least those who enter into contracts with registrars, eg: registrants) just what that means. This accreditation implies that there is some minimal level of technical clue (there are accredited registrars who have technically failed), and some might think it implies a minimal level of business ethics (and there are numerous accredited registrars who have flunked that test).
As the FTC and US courts (and possibly even the postal service) have now shown a willingness (and blinding speed compared to ICANN) to go after VeriSign, I think it is only a matter of time before similar mechanisms kick in to regulate some registrars. The question can then be raised why ICANN has encouraged and protected such cowboys, and the most reasonable answer is: money. -g