The reason why I am sensitive to tax bureau phone calls is because trading Bitcoin is in a gray state of "not encouraged but not explicitly prohibited" in China. Holding Bitcoin is legal, but selling Bitcoin may be subject to a 20% tax rate on "property transfer income", similar to the US stock market. But BTC trading has strong concealment, difficult tax inspection, and unclear policies. It is difficult to be taxed without actively declaring, so cryptocurrency enthusiasts are most afraid of being targeted by tax authorities, especially KOLs.