A hacker has claimed to have procured a trove of personal information from the Shanghai police on one billion Chinese citizens, which tech experts say, if true, would be one of the biggest data breaches in history. The anonymous internet user, identified as "ChinaDan", posted on hacker forum Breach Forums last week offering to sell the more than 23 terabytes (TB) of data for 10 bitcoin, equivalent to about $200,000. "Databases contain information on 1 Billion Chinese national residents and several billion case records, including: name, address, birthplace, national ID number, mobile number, all crime/case details."