You can never say in advance what effect demonstrations are going to have. When the masses take to the streets, all bets are off. The power of demonstrations lies, it would seem, in the overtly public nature of the challenge that they pose. Authoritarian governments are especially vulnerable to being called out in this sort of way, since they often make various absolute claims to legitimacy that can be dramatically disproved when large numbers of their own citizens take to the streets. If demonstrations get big enough, they can begin to erode a government’s hold in all sorts of concrete ways, by preventing public services from being carried out or by taking physical control of certain spaces (like the crowds in Cairo’s Tahrir Square in 2011).