Apple CEO Tim Cook has issued an open letter to customers in a bid to explain why the company will oppose an order from the United States government. Apple wants the public to understand the decision and what is at stake.

The FBI has asked Apple for help to access data on the iPhone used by the San Bernadino shooter. While Apple has done everything possible to assist with the investigation so far, the security features inherent in iOS make it impossible to access a user’s personal data without the passcode. Even Apple has no way in – Cook says “the contents of your iPhone are none of our business.” The government is asking Apple to actively create new software which could compromise security for millions of iPhone users worldwide:

“Specifically, the FBI wants us to make a new version of the iPhone operating system, circumventing several important security features, and install it on an iPhone recovered during the investigation. In the wrong hands, this software — which does not exist today — would have the potential to unlock any iPhone in someone’s physical possession.”

Cook has spoken out on many occasions about the importance of strong encryption, and the dangers of creating a backdoor which could unlock any iPhone. Describing the demands as “chilling,” he goes on to explain that purposely building weakened software for a single use could have much bigger repercussions, creating the potential for surveillance software to be created or an iOS “master key” to fall into the wrong hands; it would be safer for the backdoor technology not to exist in the first place.

“While we believe the FBI’s intentions are good, it would be wrong for the government to force us to build a backdoor into our products. And ultimately, we fear that this demand would undermine the very freedoms and liberty our government is meant to protect.”

If you want to know more detail, the full letter is available on the Apple website – it’s definitely worth a read.

Related: Privacy Policy: what does Apple do with our personal data?