Some of my friends questioned about the safety of backpack travel. Of course you have to be aware that you are the one who are responsible to your safety. No one will protect you. But backpacking is not something scary. I think not many people want to risk own safety.
Most people know how to stay away from dangers and they do stay away.
If you know what you are doing, you are all right. Stay away from obvious dangers, then backpacking becomes safe travel. I stay away from dark streets, and walk big streets, which have many people walking. If someone told me dangerous areas, I stay away from them. Doing these little things, I feel pretty comfortable during my trips.