of it all. the greek prime minister asex lis tsipras announcing a shock referendum on the bailout terms. it didn t end there. throughout that day he tweeted 23 times, each more defiant than the last. we don t need to ask permission to let the voice of the greek people to be heard. reporter: the crisis escalated parallel protests unfolded on the streets and on twitter. the greek finance minister even tweeting out his resignation. today there is an expectation of transparency. there s a lot of politics that take place on twitter. and it can be perilous. some of these negotiations are extremely complex. reporter: they don t come much more complex than a nuclear deal with iran. to say key parts of this historic moment played out on twitter would be an understatement. on the day the deal was reached,