What is it about parks? From People’s Park in Berkeley to Uhuru Park in Nairobi to Gezi Park in Istanbul, governments have violently suppressed grassroots opposition to plans to convert public land to private use. At 4:30 a.m. on May 15, 1969, “Bloody Thursday,” California Governor Ronald Reagan’s unannounced decision to send troops to take back “People’s Park”* left one student protester dead, another blind and hundreds more hospitalized. In 1992, Kenyan President Daniel arap-Moi ordered his thugs to beat Wangari Maathai unconscious for protesting the proposed construction of a 60-story office complex in Uhuru Park. (Maathai received the Nobel Peace Prize 12 years later.) Last Saturday night Turkey’s Prime Minister Recep Tayyip Erdogan ordered the storming of Gezi Park, where protests against replacing the last significant green space in Istanbul with “an Ottoman-themed shopping mall” had escalated into broad rage against the government.

Three parks, decades and worlds apart, become epicenters of popular protest, which three elected officials brutally crush. Why? Parks are the epitome of the people’s land, open to all, owned by none. They are some of the last refuges from the chaos of modern urban life. And the public insistence on their sanctity threatens the growing determination of corporate and political institutions to sell off what little remains of the commons.

These places of tranquility have become battlegrounds for all who oppose privatizing the public square. Parks are the antithesis of the gated community, and their protection is everyone’s fight.

*The University of California at Berkeley owned the land.