Beijing has long built walls between Chinese citizens and the outside world: The Great Firewall blocks out information, and passport controls and exit bans restrict movement. But money had been different. 北京长期以来在中国公民与外部世界之间筑起高墙：“防火墙”阻断信息，护照管控和出境禁令限制人员流动。但资金流动曾经是个例外。…