BBC News - Beijing to crack down on 'black jails'

Beijing's public security bureau has launched a six-month crackdown on so-called black jails operated by private security firms in the Chinese capital.

Local governments hire the firms to stop people who travel to Beijing to voice grievances about perceived injustices in their areas.

The police say the firms are involved in illegal detention, violence and running underground jails.

The government usually prefers not to admit these kind of operations exist.