(A photo of Iranians defying a ban to protest last Friday's Presidential election. See many more photos of the protests here.)
Twitter delays a network upgrade due to it being used as a communications tool in Iran:
A critical network upgrade must be performed to ensure continued operation of Twitter. In coordination with Twitter, our network host had planned this upgrade for tonight. However, our network partners at NTT America recognize the role Twitter is currently playing as an important communication tool in Iran. Tonight's planned maintenance has been rescheduled to tomorrow between 2-3p PST (1:30a in Iran).Wow. The world is changing before our eyes -- on many fronts.