BEIJING — When vicious inter-ethnic violence broke out in Urumqi last year, Chinese authorities flooded the city with security forces. But next came an unexpected step: they cut off internet access across the vast north-western region of Xinjiang. Controlling the information flow was as crucial as controlling the streets, it seemed. Eight months on, the net remains largely inaccessible in Xinjiang, though officials claim it will soon be restored. The small number of sites that were recently unblocked are heavily censored; only a severely restricted email service is available. The internet blackout is partly an anomaly, made possible by the region’s poverty and remoteness. It is hard to imagine the authorities gambling with Shanghai or Beijing’s internationalised economies. But it also reflects the government’s wider approach to the internet: real fear at the speed with which information or rumours can spread and people can organise. And an absolute determination to tame it. The cut-off lies at the extreme end of a spectrum of controls that experts say constitute the world’s most sophisticated and extensive censorship system – and one that is growing. Google’s decision to shut its mainland search service rather than continue to self-censor has […]