OK. So there is danger in every city. But you really need to be careful in Rio. We saw several people get robbed in broad daylight, even in the tourist areas (Copacabana, Ipanema). Mostly desperate street kids grabbing pocketbooks and making a run for it. So keep your bag secure on your body... and definitely do NOT leave valuable things on the beach unattended when you go swimming!
That's interesting. My wife and I spent a month there 3 years ago and had no problems at all. We were careful and didn't carry much, but we didn't even see a thing.
My father lives there and his apartment is across from the largest favela (name is escaping me but is it florinho?). All night long they shoot off fireworks every time a shipment is delivered successfully. Quite the scene.