Twitter CEO Dick Costolo has stressed the need to keep freedom of speech as a priority, even in times of civil unrest. Speaking at the Web 2.0 Summit in San Francisco on Monday, Costolo stood by the decision not to suspend the service or reveal user identities to authorities in the wake of the UK riots this summer. Talks between representatives from Facebook, Twitter, BlackBerry Messenger and Home Secretary Theresa May during the riots caused speculation that the government would try to temporarily suspend the digital networks.