https://www.reuters.com/article/us-china-cryptocurrency-mining/crypto-miners-halt-china-business-after-beijing-cracks-down-bitcoin-tumbles-idUSKCN2D5031 >SHANGHAI (Reuters) -Cryptocurrency miners, including HashCow and BTC.TOP, have halted their China operations after Beijing intensified a crackdown on bitcoin mining and trading, hammering digital currencies amid heightened global regulatory scrutiny of them.