Earlier quoted context omitted.
As a middle-income tourist who has had multiple holidays in Rio, the closest I've come to being robbed was by a taxi driver that wanted $200 to travel from Corcovado to Pao de Acucar. Seriously, it's like any other city in the world. If you walk around a dodgy area talking on an iPhone, by yourself, especially late at night, then you're asking for trouble. Be sensible and cautious, and Rio is a lovely place to go on…
https://www.youtube.com/watch?v=if6GLohPq8k Not that incidents like this don't occur in other cities in the world, but it shows that avoiding dodgy areas at night might not be enough.
The only other place I have seen it like the above is the gypsy kids in Rome. Even then though they were more slight of hand pick pockets than the blatant assault in the video.