I had this problem in Baoshan, but solved it through buying a map to track down the police station. Having arrived there, I explained my predicament, and the nice policeman made a phone call, then gave me the address of an Internet bar I could use. Presumably he'd told the boss "This foreigner wants to go on line, let him!" Couldn't have got that result without Chinese expertise mind.

Many copy shops have computers and no ID checking.

@gongsun
Hate to burst your bubble, but more presumably, the bar has a "relationship" with someone at the police station.