I'll spend a few days in Sao Paolo soon, and I've been warned by some people to not go out when it's dark, to always leave everything valuable in hotel, to not take taxis etc., basically to be very, very cautious.

Now, I've been told the same about a lot of foreign cities (including infamous Barcelona, Guangdong, Bangkok..) and it was never ever a problem to be there at night, but I do understand that Brasil is a different matter.

How carefully do I really have to be? Is there anything on wearing clothes which helps NOT to be robbed/attacked? Any other hints? I certainly want to keep my "never robbed" statistics Maybe have only very little cash with you, and pay almost everything in credit cards? (Is that possible in restaurants/stores there?)

Thank you very much and I hope those questions haven't been asked before (did a quick search but couldn't find anything)