An ad agency's use of some of Austin's homeless as wifi hotspots during the SXSW festival has become a hot topic itself in the first days of the event.

As part of what it calls "a charitable innovation experiment," BBH Labs has outfitted 13 homeless people with wireless routers as part of a "Homeless Hotspots" initiative. The effort, which is not affiliated with the festival, is designed both to improve connectability for SXSW Interactive attendees and to provide a community service to the city's homeless community.

But BBH has come under fire by some critics who see the stunt as exploitative, while the company maintains that there is no profit incentive for anyone other than those participating homeless, who get to keep any money they earn through Paypal donations for access.

"Each of the Hotspot Managers keeps all of the money they earn," says a statement on the BBH website in response to the criticism. "The more they sell their own access, the more they as individuals make (it's not a collected pot to be shared unless people choose to donate generally)."

The program, which is partnered with local Austin shelter Front Step, runs through Monday and is inspired by the street-newspaper model homeless organizations have used for years.

BBH New York's Saneel Radia, who conceived of the idea, has been vocal online in defending Homeless Hotspots even in the face of criticism: "Obviously, there's an insane amount of chatter about this, which although certainly villianizes us, in many ways is very good for the homeless people we're trying to help: homelessness is actually a subject being discussed at SXSW and these people are no longer invisible," he said in a blog post.