In all likelihood in the mid-1990s the National Security Agency was listening to the communications traffic flowing through the Umm Haraz satellite ground station outside Khartoum, Sudan.
The reason: Osama bin Laden then lived nearby. According to an expert on the history of US eavesdropping, the NSA had identified the phone numbers used by Mr. bin Laden and key associates. Intercepts yielded a trove of data about the financing and organization of the fledgling Al Qaeda.
Fast forward to 2006. Bin Laden has decamped for parts unknown, and the NSA has no Umm Haraz equivalent. Al Qaeda's communications no longer follow a well-worn track that's easy to intercept.
It's in this context that the current controversy over the NSA's domestic eavesdropping activities might be seen, say some experts. The nation's biggest and most secretive intelligence agency is struggling to tap an adversary for whom the very nature of communication has changed.
Following the 9/11 terrorist attacks, President Bush authorized the NSA to eavesdrop, without a warrant, on the international communications of people in the US, when the agency believed those communications were linked to Al Qaeda.
Revelation of this program in a leaked story in The New York Times in December sparked widespread controversy, and lawsuits. The American Civil Liberties Union filed suit against the NSA itself on Jan. 17. On Jan. 31, another civil liberties group, the Electronic Frontier Foundation, sued AT&T for its alleged cooperation with the NSA eavesdropping.