I have a big problem with the "tactical" bags from companies like 5.11 and Maxpedition.

Beyond the fact they scream "I'm carrying a gun!" they are also very vulnerable to a thief coming up from behind and cutting the shoulder strap and making off with the entire bag.

A better solution is using a camera bag like one from Pacsafe. Not only is it more discreet but the shoulder strap is reinforced with steel cable to prevent cutting.