Apple has declined to comment has commented below, and users have noticed that they can still use affected VPN apps if software came from another country's App Store. This isn't a wholesale block, then.

The move isn't coming out of the blue: China is holding its once-every-5-years Communist Party congress in the fall, and it tends to ramp up online censorship ahead of those gatherings to silence dissent. The government also made Apple pull the New York Times app at the start of 2017. Even so, it emphasizes how easily China can hold the tech industry over a barrel. China knows Apple and others need Chinese customers to thrive, and that means they have to remove apps even when they help protect freedom of speech.

The clampdown also illustrates the pitfalls of disallowing apps from unofficial sources. The iOS App Store is theoretically more secure, since you're less likely to run across rogue apps hosted on sketchy websites and less-than-vigilant stores. However, it also leaves you with few practical alternatives if censors demand that an app vanishes. You still have options on Android or desktops, even if it involves a lot of effort to track down just the right program.

Update: Apple has issued a statement noting that it pulled the apps in response to Chinese rules requiring that VPN developers obtain a government license. You can read the full statement below.