If you have an SLR camera users, you are a simple and short tips that lens and your camera more secure. Especially when you put a long lens (telephoto) in the camera body, pay attention to the way you hung the camera on his shoulder.
Note the two pictures below, there is a big difference between the two. In the left image, the front glass element lens sticking out. While the image right, the end face relative lens hidden in the back (sorry) ass.
In my opinion, the way the camera drape like in the picture to the right will make the lens more protected. If you hang a camera like the way the picture on the left, most likely due to lens hit him hard objects that stand out (imagine the lens you hit the wall, wall, door, people who walked passed etc). It would be more secure if you hide the tip of the lens backwards.
Please try. Hide behind the lens (again, sorry) your ass!