The Economist explains how social media in the sixteenth century helped bring about the Reformation:
Scholars have long debated the relative importance of printed media, oral transmission and images in rallying popular support for the Reformation. Some have championed the central role of printing, a relatively new technology at the time. Opponents of this view emphasise the importance of preaching and other forms of oral transmission. More recently historians have highlighted the role of media as a means of social signalling and co-ordinating public opinion in the Reformation.
Now the internet offers a new perspective on this long-running debate, namely that the important factor was not the printing press itself (which had been around since the 1450s), but the wider system of media sharing along social networks—what is called “social media” today. Luther, like the Arab revolutionaries, grasped the dynamics of this new media environment very quickly, and saw how it could spread his message.