If you happened to be outside City Hall on the morning of May 27, you probably didn’t look twice at the two yellow-vested guys installing a new advertisement in the JC Decaux bus shelter at Randolph and LaSalle. Not many people did, including the cops who pulled up and idled nearby. But the poster the workers slid swiftly into place didn’t tout the merits of Verizon, Altoids, or the iPod. “Are Tourists More Important Than the Poor?” asked the tagline over photos of Mayor Daley and the Bean. “If the mayor has the energy to raise $450 million for Millennium Park,” read the text, “shouldn’t he also be able to raise money for Chicago families in urgent need of affordable housing? Who will hold him accountable for this chaos?” A line at the bottom directed the curious to a Web site: chicagohousingauthority.net.

“It’s at my house,” said another man. “That’s why I called last night–”

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Charlotte (all the participants’ names have been changed at their request) says she “was truly horrified” when she first saw one of the Leo Burnett CHA ads in January, on the bus on her way to a teaching job. It featured a testimonial from a former CHA resident named Latoya Wolfe, a Columbia College student and aspiring novelist described as “determined to defy the Robert Taylor stereotype” and “thrilled” when the first Taylor high-rises came down. Some of Charlotte’s students lived in public housing, and she was seeing and hearing quite a different story. The ads, she says, were “really slick.” But they “only tell like 2 percent of the experience that people are having with the plan.”

Charlotte and the others behind CHAos had all been involved in culture jamming in the past. Many of their public art projects protested gentrification and the privatization of public space. Most hadn’t worked together before but they’d been kicking around plans to collaborate. “The majority of our first conversations always came back to these parallel things around privatization and things that are going on around Chicago specifically,” says Charlotte. “We were all really interested in what’s going on with Renaissance 2010 [the CPS’s ten-year plan for the schools] and what’s going on with the CTA. It ended up making a lot of sense when this specific thing came up. We felt like we knew how to deal with it.”

More recently, the agency got hit with an embarrassing one-two punch from the dailies. In April the Sun-Times reported that CHA contractors had contributed more than $250,000 to the 17th Ward Democratic organization over the past three years. There’s no public housing in the southwest-side ward, but CHA CEO Terry Peterson lives there and served as its alderman from 1996 to 2000. Then in May the Tribune published a lengthy report on widespread failures in the agency’s administration of Section 8 vouchers–the rent subsidies designed to help public housing residents find housing in the private market. Analysis of 230,000 CHA records revealed that Section 8 landlords had failed four out of every ten inspections over the last five years. Chicagoans displaced from public housing were ending up in buildings that often contained dangerous levels of flaking lead paint, were infested with vermin, and lacked electricity, heat, plumbing, or all three.

The installation itself went smoothly. Around 8:30 that morning a team took off from the loft and headed downtown, posters under their arms and a videographer in tow. (A second team headed south a half hour later to distribute posters in a loose arc from 39th and King Drive to California and Milwaukee.) When they hopped out of the car on Hubbard, under Michigan Avenue, they donned the yellow safety vests.

While the activists were talking the hotline rang. Charlotte answered it and moved into the kitchen to talk. When she returned she shook her head and laughed. “That was Eric Klinenberg,” she said. Klinenberg, a sociologist whose 2002 book Heat Wave offered a blistering critique of the city’s response to the 1995 heat emergency that killed as many as 739 people, had been sent the link to the Web site by a friend.