"The only way you can write something that survives is that someone who's your diametrical opposite can agree with it," says Jimmy Wales, a founder of Wikipedia. Urban planners and criminologists talk about the "broken window" syndrome, says Ward Cunningham, who came up with the first Wiki software in the 1990s. If a neighborhood allows broken windows to stay that way, the neighborhood will deteriorate because vandals and other unsavory people will assume no one cares. Similarly, a Wiki draws strength from its volunteers who catch and fix every act of online vandalism. When the bad guys learn that someone will repair their damage within minutes, and therefore prevent the damage from being visible to the world, they tend to give up and move along to more vulnerable places.