From the outside, the actions of Chinese state security can often read like an absurdist black comedy. For those living under its jurisdiction, however, it can create a Kafkaeque nightmare. As several Chinese filmmakers have recently found, alleged offences are often unclear and punitive restrictions can be imposed without notice or warning.

Chinese documentary maker Hu Jie, for example, was prevented from leaving China last month. As recently as late last year, he was able to visit the Special Administrative Region of Hong Kong, which mainland Chinese need a permit to enter. However, when he applied for a visa to attend a screening of one of his films at Nepal's Film Southasia festival, mysterious obstacles appeared in his path.