I've been in Mexico (Playa del Carmen) for almost 19 months now. Traveled to Acapulco and other places in our area. Unless you don't use common sense (as @anomadsoul stated) or hang with the wrong crowd (the really wrong crowd) you are safer here than in many cities in the US or even Europe.
I've been riding my bicycle home from the city center (6 km) in the middle of the night and even then I've never felt unsafe.