CHICAGO (CBS) — The teenage robbery mobs are at it again on North Michigan Avenue. Some 50 young people barged into a Walgreens at Michigan and Chicago on the Magnificent Mile on Tuesday afternoon. They took bottled drinks and sandwiches off the shelves, then ran off, CBS 2′s Suzanne Le Mignot reports. A police report says authorities were able to nab three of the thieves. Walgreens says the store is working with police, helping investigators with video from the store security camera. The Mag Mile earlier this year was hit by similar mobs of young thieves. Attacks on commuters and...