Twitter vice president Colin Crowell talks about how online platforms, like Twitter, play a key role in connecting people and spreading ideas. Crowell describes how Twitter, which allows for anonymity through the use of pseudonyms, encourages freedom of expression. He cautions that governments also try to limit this expression and control the flow of information by requesting that certain tweets be removed – or even by blocking Twitter completely. Crowell highlights how Twitter has been used to start various online social movements,citing several successful case studies from around the world.