Julius Genachowski ran Obama's Federal Communications Commission for four years. His most prominent move was his push for Net neutrality regulations, generally favored by content companies and opposed by networks.

Today we learn that Genachowski is joining buyout giant KKR.

This helps undermine Obama's promise to end the revolving door. But it's hardly the most audacious FCC revolving-door move. Recall this former FCC Commissioner Kevin Cox from decades ago:

He voted on several landmark items that opened up the Bell System-era AT&T to competition and then joined MCI, the company that benefited from those rulings while doing as much as any institution to break up the phone company monopoly. (Cox later went to the law firm that represented MCI.)

There's a lesson in there for regulators: meddling in businesses' business is good for business.