That 15 big data companies, among which one is newly listed, are being investigated on the charge of selling customers' data exposes the lack of rule of law in the booming industry.

Big data is a promising technology, which can enable people to see human activities from different perspectives. Thus big data can be used as reliable references for decision-making.

But the ongoing investigations into the 15 companies' activities show the potential criminal risks in the big-data industry, which not only infringe upon people's privacy rights, but also aggravate social inequality.