1. Riding in a bus at night (those things were well lit and sort of like rolling fish bowls), we were standing in the middle, holding on to the overhead bar. I watched a guy on the street look right at us, wind up, and throw a large rock (like a cobblestone) directly at us. It shattered a bus window, flew right past our heads, and then shattered a window on the other side on the way out. The bus driver wanted nothing to do with that neighborhood at night, and he gunned it. We looked at each other like "did that just happen?" I don't know if that rock could have killed us, but it would not have felt good to take in the face.
2. We were walking out of a favela where we had just taught a referral. We watched a minivan of policia pull up, unload in a hurry (machine guns in hand), and charge into the favela apparently to mix it up with the drug lords who were in charge there. We got out of there post haste, and I am sure the bullets were flying in both directions very soon after we cleared the area.