As other tech firms consider pulling out of China amid the country's aggressive anti-monopoly campaigns, Apple is looking at how it can expand its presence on the mainland and turn more shoppers into Apple Payers.

China is the world's largest mobile market, though it comes in behind the U.S. and Europe in terms of Apple consumerism. Apple CEO Tim Cook recently set off to China to change that.

"In the future, China will become Apple's biggest revenue contributor," Cook said (subscription required). "It's just a matter of time."

Cook said Apple plans to step up its retail store presence in China from 15 locations to 40, in just two years time. He said the four Apple stores in Beijing serve approximately 225,000 customers each week, suggesting they might be the busiest retail stores in the world.

Cook met with Chinese Vice Premier Ma Kai in Beijing's Zhongnanhai, central government headquarters, to speak openly about privacy.

There is speculation that, due to the time of the meeting, Cook met with the vice premier to discuss recent the man-in-the-middle (MITM) attacks launched against Apple's iCloud servers in China.

Chinese news organization Xinhuanet reports Cook and Kai "exchanged views on protection of users' information" and "strengthening cooperation in information and communication fields."

Though Apple said the attacks didn't breach iCloud, privacy watchdog group GreatFire said the MITM attacks siphoned sensitive data en route to or from the servers. GreatFire went even further, alleging all signs pointed to the Chinese government as the perpetrators behind the attacks.

Chinese officials adamantly denied having anything to do with the iCloud attacks and the condemned the practice of hacking. GreatFire, however, links the iCloud attacks with the launch of the iPhone 6 series in China.

iOS 8's formidable encryption has peeved law enforcement agencies in the U.S. With Chinese regulators holding back the release of the iPhone 8 an extra month, there is evidence that the encryption is drawing ire abroad as well.

"When details of the new iPhone were announced, we felt that perhaps that the Chinese authorities would not allow the phone to be sold on the mainland," stated GreatFire. "Ironically, Apple increased the encryption aspects on the phone allegedly to prevent snooping from the NSA. However, this increased encryption would also prevent the Chinese authorities from snooping on Apple user data."