 So far, we've heard a lot about the scammers, but we haven't actually heard them. Su, as he wants us to call him, is a Chinese student studying in Japan. My BBC colleague Yi Ma contacted Su after he posted about how a fake police officer persuaded him that he was suspected of money laundering. Su was on a call with the scammers for seven hours. And when he was allowed a bathroom break, he managed to contact a friend who told him he was being had.