The Hong Kong police recently launched a law enforcement operation code-named "Double Gun". They arrested three men and one woman at the Hong Kong branch of a cryptocurrency money laundering syndicate in an industrial and commercial building in Tsuen Wan. It is reported that the criminal syndicate actively promoted through social platforms, SMS and mobile applications, and offered attractive discounts, such as "new member registration discounts" or "real money in, cryptocurrency out". The investigation found that the group has received more than six hundred million Hong Kong dollars in operations so far, which is quite alarming.