Bitcoin and other cryptocurrencies sold off Friday after China took a hard line against the space . The People’s Bank of China in a Q&A overnight called all crypto-related activities illegal — the latest in a regulatory crackdown that had previously targeted activities such as mining. Craig Johnson, chief market technician at Piper Sandler, said the latest announcement is more bark than bite. “The whole discussion that this is going to be made illegal, I don’t think that’s ultimately going to play out. We’ve heard this time in and time out,” Johnson told CNBC’s “ Trading Nation ” on Friday,...