Man, when I was still on the same hosting company like Joey, my bandwidth was always higher than 40Gb/month. Now that I'm with the new company, and I had the ability to not allow external linking, my bandwidth has gone to 30Gb/month. And, I now have more files online than before. I can also see where the excess bandwidth came from. Some people had wallpapers from my site in their signatures on forums. It's crazy. Well, now all they see is a little red cross
And they are lucky.. I can redirect external request to a standard image too, and then put a message in it "please don't hotlink".... or I could use a picture of a naked man instead