So I'm wandering around before class, taking pictures in puddles around a church (the weather was so weird to day - it cycled from pouring rain and flooded streets to sunshine about four times throughout the day), when this boy comes up to me. He points at my camera, and I think he wants a picture. I ask him if he'd like a picture and he agrees. I take a few, he takes a huff, then I thank him and head off to my class. He follows me, asking for something, pointing at my camera. I don't recognize what he's saying (he wasn't using any word I had heard for any kind of money, and I've heard them all), and tell him so.
He snatches my sunglasses and peals off, so I put my camera away and follow him, as he wasn't running away that hard. I catch up with him half a block away and start asking for my glasses back. A homeless guy comes up and asks what the kid took (at least, I think so, I had a really hard time understanding him. For some reason, he thought I was Russian). I got my sunglasses back and a reprimand that I shouldn't take photos of the kids. I thanked him and told him the kid asked me and I asked him.
Moral: Make sure both sides are clear on the transaction. Of course, I wouldn't have followed the kid if I hadn't been in a decent neighbourhood with people around outside a church in the middle of the day, but be aware when you're taking pictures.
That said, this is a small indication of the poverty that can be pretty easily seen here daily. Argentina is still a third world nation in reality; Buenos Aires is an anomaly in the eighth-largest country in the world.