Public prosecutors in Shanghai warned of a sharp increase in theft of personal information online, with criminals stealing and selling data for various criminal purposes, ranging from telecom fraud to racketeering.

According to prosecutors, there was only one such case involving eight suspects during the first half of 2012, but the same period in 2013 has seen 30 cases involving 57 suspects.

"More than half of the suspects committed the crime by taking advantage of their positions, and their motive is to promote products or obtain money by the transaction," Gu Xiaomin, director of the public prosecution division of the Shanghai People's Procuratorate, said at a news conference on Monday.