18 MongoDB databases with information generated by accounts on several online social services in China have been sitting on the web ready for plucking by anyone knowing where to look. The program vacuums into one large database the account information from six social platforms in China and links it to a real person or ID. The parties at the end of the distribution chain are police stations in cities or provinces. The data is then distributed over police stations per city/province to separate operators databases with the same surveillance network name.
Source: https://www.bleepingcomputer.com/news/security/open-mongodb-databases-expose-chinese-surveillance-data/