Probably only in the U.S, and even so probably hard to regulate anyways due to nature of cryptos
2. Unless you coordinate internationally, the nations with less regulation will launch successful businesses on it and dominate the market - imagine US having some crazy internet regulations in 1996, and other nations not having them. We'd be having this discussion now not on Hacker News, but on Новости хакера, or on 해커 뉴스. And US economy would be a few (dosen?) trillion dollars poorer.