http://www.cnn.com/2011/US/05/16/bin.laden.visitors/index.html Unnamed intel officials claimed that U.S. intel didn't have eyes on UBL the entire time he was in the Abbottabad compound because they didn't want to risk tipping him off.
The CIA did not need to put agents with binoculars in the bushes nearby. This also discounts the use of inside informers and double-agents, and al Qaeda has long been riddled with them.
Indeed, elint and overhead surveillance would not tip anyone off inside that compound, unless the Pakistani military caught on that stealth drones were hovering overhead. They don't fly them like that, anyway, in an environment where there is any chance of detection. Also, they're not reliant upon photography. Surveillance craft and satellites use side-scanning radar from miles away. Even the optics on normal and infrared photography are so good that the drone or sat doesn't have to be directly overhead or nearby.
This is from yesterday's CNN report. Notice the concerns about "information sharing across (agencies of the US) gov't"! What does that tell you? Who would worry about that? Someone must be asking some inconvenient questions, and not getting satisfactory answers, so they've had to modify the handout yet again.
The U.S. did not have constant surveillance of the compound, in part because the U.S. did not want to tip off bin Laden or the other occupants that they were being watched.
The official also expressed concern about the amount of information being leaked about the contents of the materials obtained from the compound. The "degree of sensitive information that has walked out the door is troubling," said the official, adding, "The floodgates have opened on very sensitive information. People need to take a deep breath and use some discipline."
It is "appropriate" to have robust intelligence sharing on terrorism, but the amount released could have "the unintended consequence" on greater information sharing across the government, the official said.