The PBOC took a strong stance on cryptocurrency exchanges in early 2017, beginning with a meeting with representatives of the major Bitcoin exchanges in China (BTCC, OKCoin and Huobi) to urge them to focus on compliance with regulations related to exchanges. This lead to a decrease in trading volume in China, and eventually the major Chinese exchanges halted withdawals and shut down fiat trading. A lot of trading volume was coming from Asia, so this painted a grim picture for the future growth and adoption of cryptocurrencies.
As far as I can remember, there are no Chinese related at that time. PBOC grew concerns about the so-called bitcoin exchanges, offering "no trading fee", and they realized that something is not right from behind and there could be manipulation or even fake volumes.
And that's how this whole crackdown started. The PBOC even called them just a "website" and not exchange, and so the rest is history.
Anyways, good list and I'm sure we look forward for more insights in the next ten years.