Studies suggest the approach can work: 47 percent of the crack users surveyed in Sao Paulo said they'd welcome treatment, according to the Federal University of Sao Paulo study.
Ethel Vieira, a psychologist on the raid team, thinks their persistence is paying off.
"Initially, they'd run away, react aggressively, throw rocks," she said of users. "Now most of them understand our intention is to help, to give them a chance to leave the street and to connect with the public health network."
Human rights groups object to the forced commitment of children, saying treatment delivered against the will of patients is ineffective. They also oppose the sweeps, which they describe as violent.
"There are legal procedures that must be followed and that are not being followed. This goes against the law and is unconstitutional," Margarida Pressburguer, head of the Human Rights Commission for Brazil's Association of Attorneys, said during a debate last year.
Rio Mayor Eduardo Paes suggested in October that the city would start forcing adults into treatment. "A crack addict isn't capable of making decisions," Paes said from the Jacarezinho shantytown in the week after police stormed the area and seized control of what was then Rio's largest cracolandia.
The Rio state Attorney General's Office responded by telling city officials "the compulsory removal of adults living in the streets has no legal foundation." It said adults can be committed only when they become a danger to themselves or others and outpatient treatment options have run out.
"They give us a place to sleep, food, clothes, everything," said Bobo. "I've been picked up by the city and I liked it. They are doing this for our good."
But even as Bobo endorsed the city's approach, a friend was stepping over to the drug stand for more cocaine. Bobo asked for $5 worth of drugs — cocaine for now, crack for later. Then he rolled up a bill and dumped a small mound of white powder in his palm for snorting.
With a nose full of cocaine, he set off, ready for another day.