The big breakthrough in finding Osama Bin Laden came when intelligence analysts first noticed the million dollar compound in Abbottabad, Pakistan didn't have internet access. Next, the analysts observed the occupants never took their garbage to the street (like the other neighbors did) and instead preferred to burn it inside the compound. Finally, they knew a male occupant lived in the house but they never saw him outside.
Putting together the three clues — each of which is a wonderful example of seeing what isn't there — was enough to help the analysts unlearn the idea that Bin laden was living in cave somewhere in Afghanistan and was instead "hiding in plain sight."
P.S. If Author Conan Doyle, the author of the Sherlock Holmes books, were alive today I think he would have been pleased at how the intelligence analysts finally came to locate Bin Laden. It was similar to the way Holmes once solved a crime by noticing the curious case "of the dog that didn't bark."