Apple hobbled a crucial tool of dissent in China weeks before widespread protests broke out

Anti-government protests flared in several Chinese cities and on college campuses over the weekend. But the country’s most widespread show of public dissent in decades will have to manage without a crucial communication tool, because Apple restricted its use in China earlier this month.

AirDrop, the file-sharing feature on iPhones and other Apple devices, has helped protestors in many authoritarian countries evade censorship. That’s because AirDrop relies on direct connections between phones, forming a local network of devices that don’t need the internet to communicate. People can opt into receiving AirDrops from...