I have a variety of backpacks and rucksacks ranging from military surplus to a new Kelty Redwing that I got for my birthday. I am currently in the process of beating that one up. I believe that no matter if you carry your 'stuff' in a shiny new technical pack or a stolen shopping cart, the fact that you have 'stuff' will make you a target of those who don't. That said, you don't want to look like an exclusive sporting goods store model either. If you have to travel, travel light, wearing and/or concealing what you have. Depending on the situation, if you can shelter in place and protect your shelter, your odds of survival improve IMHO.