The Great Firewall could easily block the foreign internet for most users in China; an unexplained glitch actually made this happen by accident one day last year for a couple of hours. Some large enterprises, banks and foreign companies have leased their own lines out of China, which might need to be shut down separately. As for the domestic internet, which would be of most concern to the party, shutting down the countryâ€™s home-based internet service providers, and with them access to microblogs, video sites, bulletin boards and the rest, should be within its capabilities.
But would the party dare? In the Arab spring flipping the kill switch was no help to the dictators of Egypt, Libya and Syria. For China, even if its big cities were torn by riots, turning off the internet would seem to run counter to its operating logic: adjust the machinery, intensify filtering, round up far more than the usual suspects, but do not give the people added reason to go out into the streets. The kill switch may be necessary as a last resort, but using it would be an admission of system failure.