“Amanda Maia was visiting Rio de Janeiro for the weekend earlier this month with her mother. It was a sunny day and so they went to Ipanema beach to catch some rays. She says she noticed a few groups of kids.
‘There were lots of gangs, about 10, 15 children each; they were about 10 or 12 years old,’ Maia recalls.
At first, she says, they were just roaming the streets, checking people out. The ones she saw were smoking marijuana, too.
According to video shot about the same time, the gangs suddenly swept over the beach, stealing phones and snatching jewelry.”
Source: Swarming Thieves Wreak Havoc On Famed Rio Beaches : Parallels : NPR