I was mugged on avenida Paulista, there were plenty of pedestrians around. I screamed on top of my lung, nobody came to help, the bad guy did a "grab-and-run" and was already out of sight in one split second. I was traumatized and shaken. Two guys came asked me what happened, I told them. They then said, well this is Brazil, we have to go now, take care. (I think when they realized I was a foreign visitor, they thought I could certainly afford to replace what I have lost, so it was no big deal)