Users of Apple's iCloud services in China are being forced to share their data with a state-run Chinese company.
Apple flagged the change to customers this week, advising them to read the terms and conditions of an agreement that hands operations of iCloud in mainland China to a company owned by the government of Guizhou province.
The terms include a clause that Apple and the Chinese company "will have access to all data that you store on this service, including the right to share, exchange and disclose all user data, including content, to and between each other under applicable law."
They apply to anyone with iCloud accounts registered in mainland China, according to Apple.
Apple made the move to comply with the country's latest regulations on cloud services. Beijing's controversial cybersecurity law, which went into effect last July, requires companies to keep all data in China.
Critics have blasted the law, saying the regulations force tech companies to be complicit in censorship and violate people's privacy rights. Beijing has said the measures are necessary to help prevent crime and terrorism, and protect privacy.
As it works to comply with the rules, Apple is reassuring users in mainland China that even though their data is being stored on Chinese servers, it will be protected.
"Apple has strong data privacy and security protections in place and no backdoors will be created into any of our systems," the company said in a statement Wednesday.
The company taking over the Chinese iCloud operations is Guizhou-Cloud Big Data (GCBD).
Apple announced the deal with GCBD, which included building a $1 billion data center in the southwestern province, in July.
Amazon has also struck partnerships with two Chinese companies to operate its cloud services in the country.
For Apple users, iCloud is typically a place to store data such as music, photos and contacts.
Apple said it will give users in China plenty of opportunities to consider whether they want their data to be stored on Chinese servers, where it will be accessible to GCBD. But its advice to customers on what they can do isn't straightforward.
Chinese users will have to deactivate their iCloud accounts if they don't want GCBD to have access to them.
Non-Chinese users whose iCloud accounts are registered in mainland China but who aren't living in the country have another option. They can change their Apple ID setting to the country or region where they currently live in order to keep their data away from GCBD, Apple said.
But it didn't offer any advice on what the options are for non-Chinese citizens who still live in mainland China.
"Because of our commitment to transparency, there will be a series of customer communications over the course of the next seven weeks to make sure customers are well informed of the coming changes," Apple said.
GCBD takes over as the operator of iCloud in China next month.
-- Serenitie Wang contributed to this report.