If he is in the U.S. he must register as a broker / dealer to operate Bitfunder, whether he allows U.S. residents to participate or not.
What I don't understand is why does he not register? The person who bites the bullet and offers the first US legal Bitcoin stock exchange stands to become billionaire rich over the next decade. People join startups and risk 5 years of their life for an opportunity such as this. Ukyo stands to gain so much if he navigated the system instead of playing games.
Anyway, once the crowdfunding law comes into effect someone will dominate this space, be that Bitfunder or someone else.
The crowdfunding regs have nothing to do with operating an exchange. And far from making an exchange owner rich, the new regs are probably the final nail in the coffin of BTC securities. If the regs make it significantly easier to raise money, few companies will choose to limit themselves by issuing BTC denominated securities. They will issue in USD to take advantage of the larger (by orders of magnitude) market of investors.
As for Bitfunder, any BTC exchange would have to comply with the same rules and regulations as existing USD broker-dealers. Specifically:
A broker-dealer may not begin business until:
it has properly filed Form BD, and the SEC has granted its registration;
it has become a member of an SRO [Self Regulatory Agency];
it has become a member of SIPC, the Securities Investor Protection Corporation;
it complies with all applicable state requirements; and
its "associated persons" have satisfied applicable qualification requirements.
Link:
http://www.sec.gov/divisions/marketreg/bdguide.htm#IIIBottom line: there isn't enough money in it to run a compliant BTC securities exchange. The market is too small and it will be even smaller when companies can crowdfund in USD.