This vein of play experimentation explores and exposes urban structures and practices, targeting the urban order and its role in moulding social and spatial dynamics. As a form of intervention, it works to locate and often contest accepted boundaries, exclusions, and conventions, and it is often more confrontational and politically oriented than the former type. For example, Free Parking Space (2005) is an initiative organized by a loose, temporary collective called “The Pedestrian Mob”. First, the group designs and builds car frames out of cardboard rolls scavenged from recycling bins that could be worn either by cyclists or by pedestrians. Then, individuals walk or ride with these frames on the streets of Toronto, occupying the same amount of physical space generally allotted to cars, humorously inverting the urban spatial order.10 This so-called auto-intervention advocates “creatively freeing parking spaces—for performance, for play, and for engagement with the politics of pedestrianism and public space” (2005, 49). By taking up parking spaces or slowing lane traffic, Free Parking Space highlights the privileging of cars in urban space, inspiring a host of vehement reactions as well as support and participation by intrigued passers-by. During one excursion, individuals were ticketed for careless (or rather “carless”) driving; thus, the intervention also makes clear what the legal limit point of intervention and experimentation is. This example coincides with other urban activist strategies for reclaiming public space (like critical mass), and it lodges its critique of the organization of urban life by interrogating boundaries, priorities, and prohibitions. The project engages a rather haphazard urban community—one that includes support and resistance, from kids in the park interested in the group’s assembly process, to eager participants who happen to be around at the same time, to disgruntled drivers who want the parking spot being occupied by cardboard, and to law enforcement officials who must decide if an infraction has been committed. This sort of experiment produces various levels of interactions that direct its insights into the city; it also blends the work of generating knowledge about the organization of urban life with using this knowledge as a platform for action.