From the article: “Although the police in Cairo sealed off parts of the Egyptian capital where protests scheduled on Facebook were to have taken place on Monday, opposition activists managed to stage brief rallies that resembled flash mobs, calling for an end to military rule and the cancellation of a deal to surrender two islands to Saudi Arabia…The fact that Facebook is now so closely monitored by the security forces prompted one leading activist to offer an online tutorial in how to use a new tool, the encrypted messaging app Signal, to help protesters find each other on the city’s streets, and stay one step ahead of the authorities.”
Read the full article from The Intercept here: https://theintercept.com/2016/04/26/facebook-no-longer-secret-weapon-egypts-protesters-turn-signal/