Favelas, in Brazil, should be mapped in Waze and users alerted everytime that a proposed traject would enter in one. From a quick search in local
Social Media, you can find history about assaults, robbery, thefts and even murders of waze users that inadvertently followed waze in the middle of a Favela.
Some police offices in Brazil already calls it "the waze victims". And, I'm hearing more and more people complaining about this issue. Yesterday, I almost entered in a Favela following Waze instructions and I can understand what people was talking about...

Hope this can help to save lifes.