https://www.theverge.com/2018/2/28/17055088/apple-chinese-icloud-accounts-government-privacy-speed

Today Apple formally transferred its Chinese iCloud operations to a local firm in southern China. It also began hosting its iCloud encryption keys in China, instead of the US, for the first time. The move has been expected since last year when Apple announced its partnership with Guizhou-Cloud Big Data (GCBD), a Chinese firm supervised by a board ran by government-owned businesses, with close ties to the government and Chinese Communist Party.

Apple users with iCloud accounts registered in China will now have their data hosted by the GCBD center. Users who don’t want their data handed over can choose to delete their Chinese iCloud accounts. Apple has told Reuters that it won’t transfer accounts over to the new data center unless users first agree to the updated terms of service.