TüBus umsonst! is a campaign for free public transportation in the city of Tübingen (pop. 82,000 in Southwest Germany). The city runs a well developed bus system, but fares are expensive. The campaign is centered by the group ZAK³ (gegen Kapitalismus, Krieg und Kohlendioxid — against capitalism, war and carbon dioxide) and is being supported by many more. The campaign has published a large booklet about its actions, reactions, and reflections.