Crime is apart of life no matter what city you are in around the world. You could be in New York City, Washington, D.C, or even Des Moines, Iowa and get robbed by somebody on the street. While traveling through South America (Buenos Aires in particular) you will start to hear stories of people getting cameras, money, or even Ipod's stolen while walking down a street.
I traveled through South America for almost 6 months, and I lived in Buenos Aires for almost 2 months. I had no problems with people trying to rob me, nor did I have anything stolen from me during this time period! Again, I had zero problems. So do not listen to people who say South America is too dangerous to travel through, because if you are a smart traveler you will avoid shady situations. During my trip I was careful about not flashing money in the streets, I would take pictures and then put my camera back in my backpack, and I didn't wear any jewelery.
While I was living in Buenos Aires I had a friend in town from the States named Dora. Dora and her mother were staying in a very nice hotel about 2 blocks from the casa rosada (very tourist area in the center of town). On the first day of the trip they were eating in their hotel's restaurant that is located in the lobby. The restaurant had a security officer that allows you to enter and leave the restaurant by checking your name on a registered guest list. Her mom put her purse down on the table when she got up to get in line for a buffet style dinner. When she returned her purse was gone, and "nobody" saw anything. There was nothing that she could do, and she was in a "secure" location. She reported this to the police, but in reality there is nothing that you can do to get your belongings back.
Check out this story about the Bush Twin's that were traveling in Buenos Aires the same time as me. If you notice in the story it even mentions the secret service were present when Barbara had her purse stolen. The thief's in Bs As are good. If you put anything down and walk away from it then expect it to be gone when you get back! Don't trust that somebody is going to watch your bag in South America because it doesn't happen.
The last story I am going to tell you about is about a traveler that was sitting in a park close to the barrio Reclota. This girl had her camera in her lap while she was just hanging out in a park. All of a sudden a man walked up to her and pointed a gun at her and said give me your camera. I would like to think that if she had her camera put away while she wasn't using it that nothing would have happened to her. If you do get robbed, just give them whatever they want. There are crazy people in this world and giving them a camera or pesos is worth not getting hurt.
Buenos Aires is a safe city, but you do have to realize that the lifestyle is very different from the states. Crimes do happen, and there is not much you can do if you are a foreigner. The most popular thing that is robbed from travelers is electronics. It is very expensive to buy camera's, Ipods, etc. in Argentina, because of the effects from the economic crisis in 2001. If you are a "smart" traveler and avoid shady situations then you will be able to enjoy the best city in the world!