Pope's First Tweet 12/12/12
"Dear friends, I am pleased to get in touch with you through Twitter. Thank you for your generous response. I bless all of you from my heart."
Similarly, Pope Pius XI was the first pope to broadcast live on radio in 1931. In the 1920's he invited Marconi to build a broadcast station of the grounds of the Vatican and Vatican Radio was launched. See here how the Vatican Radio was used over the years to bless mankind in times of war and pestilence. In their position as vicar of Christ, the popes realize the tremendous responsibility and possibilities of proclaiming the gospel through the latest form of social communication.
May God use every available means of social media in this digital age to expand the his kingdom to bring as many to Heaven as possible. After reading Jesus of Nazareth by our Holy Father, I can imagine it is no small challenge to fit the thoughts of this theological genius into 140 characters or less!