The demand applies to all content stored using what Apple calls “Advanced Data Protection” (ADP).
This uses something called end-to-end encryption, where only the account holder can access the data stored – even Apple itself cannot see it.
It is an opt-in service, and not all users choose to activate it.
This is because, while it makes your data more secure, it comes with a downside – it encrypts your data so heavily that it cannot be recovered if you lose access to your account.
It is unknown how many people choose to use ADP.
It’s also important to note that the government notice does not mean the authorities are suddenly going to start combing through everybody’s data.
It is believed that the government would want to access this data if there were a risk to national security – in other words, it would be targeting an individual, rather than using it for mass surveillance.
Authorities would still have to follow a legal process, have a good reason and request permission for a specific account in order to access data – just as they do now with unencrypted data.
Apple has previously said it would pull encryption services like ADP from the UK market rather than comply with such government demands – telling Parliament it would “never build a back door” in its products.
Cyber security experts agree that once such an entry point is in place, it is only a matter of time before bad actors also discover it.
And withdrawing the product from the UK might not be enough to ensure compliance – the Investigatory Powers Act applies worldwide to any tech firm with a UK market, even if they are not based in Britain.
Still, no Western government has yet been successful in attempts to force big tech firms like Apple to break their encryption.
The US government has previously asked for this, but Apple has pointedly refused.
In 2016, Apple resisted a court order to write software which would allow US officials to access the iPhone of a gunman – though this was resolved after the FBI were able to successfully access the device.
That same year, the US dropped a similar case after it was able to gain access by discovering the person’s passcode.
Similar cases have followed, including in 2020, when Apple refused to unlock iPhones of a man who carried out a mass shooting at a US air base.
The FBI later said it had been able to “gain access” to the phones.