I am an Angolan living abroad for as long as I can remember, and when I go back, my mother just spreads her negative feelings about the lack of security.
♦ Don't talk on your cellphone in the streets... At least not when you have fancy mobiles.
♦ When in your car, keep the doors and windows close.
♦ Never show you have expensive jewellery.
♦ Avoid the use of big handbags.
♦ Don't show you have a lot of money or willing to spend a lot when in a market.
If you're a White person, be aware you will be mistaken by the president/king/etc of your own country. Prices can increase pretty easily.
It also happens to Mixed people (like my mother and myself). When I speak, I have a tiny accent in Portuguese (the kind of accent that says I speak something else in a daily basis) and people consider me as a foreigner. What a shock I give them ;-)
♦ Don't give money to the street children. It's something difficult when they knock on your car window. it's very heartbreaking. But you give to one, you are expected to give to *every* other kid around, and believe me. They will appear by magic.
Difficult times as the rich get richer, the poor get poorer and you can clearly see the dfferences, between the new buildings and the slum...
Did I scare you yet ?
Those are just common sense things you have to do. People still go to Rio de Janeiro, right ?