Just FYI, since I'm down in Mexico City right now: Despite all the drug chaos in the north of Mexico--the state of Chihuahua has a homicide rate of 300 per 100,000 (compared to 36 in Baltimore City and 6.5 in New York City)--most of Mexico is much safer than most of America. Here's an article about the five safest places in Mexico to travel.
Even I was a little apprehensive to travel to Mexico City for vacation (mind you, just a little, as we did want to come here). It's strange, because where else in the world will you be told by various sources to 1) not take cabs, 2) not take the metro, 3) not walk, and 4) not drive? We've done the first three and have felt safer than, say, taking the subway at night in Philly or the Light Rail in Baltimore.
I can't tell just how normal and functioning this city is. You walk around, take the metro, get things to eat, look at pretty buildings, go to markets and museums, walk around random neighborhoods, eat street food... it's all very normal. Now don't get me wrong, there are stories of crime. And though we don't stick to the "safe" parts of town, we haven't walked around the supposedly bad parts of town at night while flashing dollars and taking pictures. But then why should we?
Maybe crime is more of an issue in Mexico because they have higher standards of a crime-free society. In America, it's as if we've written off huge segments of society and cities and think that it's normal to do so. What guide book would even mention East Baltimore or West Chicago or East New York, much less warn you not to go there?
The only thing here in Mexico City that isn't normal is the lack of horrible traffic and air pollution. But this week is a big holiday week (Santa Semana) and things are a bit quieter than normal as a lot of people go back to their home towns and villages to celebrate.