The headquarters of the People's Bank of China, the central bank, is pictured in Beijing, China, as the country is hit by an outbreak of the new coronavirus, February 3, 2020. REUTERS/Jason Lee Purchase Licensing Rights, opens new tabBEIJING, Nov 29 (Reuters) - China's central bank reaffirmed its tough stance on virtual currencies on Saturday, warning of a resurgence in speculation and vowing to crack down on illegal activities involving stablecoins.The People's Bank of China (PBOC) said at a co...