Early today (2011-11-17), Apple customers in China found problems buying free apps from iTunes. All of them are using iTunes accounts without credit information.
[!]Picture is from internet
When people are buying free apps in iTunes, they are asked to update their account information. If they refuse to do so, they will not able to purchase.
The accounts with credit information or Apple gift cards are not affected.
Apple currently accepts Visa, MasterCard and American Express. However, credit cards are not widely used in China, and many people’s credit cards are issued by UniPay. Thus, this action will affect many Apple users in China, the second largest market, accounted for 16 percent of Apple’s fourth-quarter sales, or about $4.5 billion.
It is unseen what Apple will do next. I will keep updating on this.
[Updated] Now the China Appstore supports Chinese accounts to top-up. The cheapest price of Apps is 6 CNY, 0.95 USD.