China Unicom is the only server here in China that offers the iPhone. They've had a problem with the reselling of the phone. Now they're trying to limit that.

Unicom says that customers who buy iPhones from them must use a Unicom SIM card or their phone will be blocked and deposits will be frozen.

China Unicom says it will check the usage of services, SIM cards and numbers via its back office systems on a monthly basis. If someone is found to be using an iPhone with another operator's SIM card, the user's number and mobile phone will be locked and a penalty will be imposed.