Backpacks are handy if you want to carry your belongings and leave your hands and arms free. But, speaking from experience, the small zipped pocket on the outside of the bag is easy for thieves to access. In a crowded situation, you will not feel someone removing something. So, my advice is, don't put anything of value in this pocket. If I remember correctly, Ruth's leather, quite expensive backpack has a small zipped pocket on the outside of the bag.