The demonstrations in Brazil began after a small rise in bus fares triggered mass protests. Within days this had become a nationwide movement whose concerns had spread far beyond fares: more than a million people were on the streets shouting about everything from corruption to the cost of living to the amount of money being spent on the World Cup.

In Turkey, it was a similar story. A protest over the future of a city park in Istanbul — violently disrupted by police — snowballed too into something bigger, a wider-ranging political confrontation with Prime Minister Recep Tayyip Erdogan, which has scarcely been brought to a close by the clearing of Gezi Park two weekends ago.

If the recent scenes have seemed familiar, it is because they shared common features: viral, loosely organized with fractured messages and mostly taking place in urban public locations.