In August, a fu san dai, the Chinese term for “third-generation rich kid”, discovered that his similarly wealthy friends in Beijing were taking a new precaution when travelling to the US. They would leave their usual smartphones and laptops behind in the Chinese capital and instead take “clean” replacements.

“They carry a second phone that has nothing on it,” this person told the Financial Times. “They take the precaution of going in [to the US] with a different phone. They leave the phone that they have in China and take a blank phone instead.” 

The fu san dai added that he and his friends did not feel they had anything to hide. But as Sino-US relations rapidly deteriorated over the summer, they heard more and more stories about friends — and friends of friends — being stopped by American “customs and border protection [agents] who would look through their electronic devices and see what was on their Facebook page or WeChat or whatever”.