China-based cryptocurrency exchange BTCC suspended all domestic trading in yuan last weekend. The decision came on the heels of a September 5 statement from regulatory authorities in China, which required all domestic cryptocurrency exchanges publish closing announcements, stop registering new users, and establish a schedule to cease yuan-denominated trading by September 15. Huobi and OKCoin — two other exchanges based in China — have announced similar plans to stop trading. To be clear: China has not banned the use of cryptocurrencies. It has banned cryptocurrency exchanges and initial coin offerings (ICOs). Even still, it has prompted some to consider whether a government might ban cryptocurrencies like bitcoin — and, perhaps more importantly, whether such a ban would be effective