Congressman Curt Weldon's brouhaha over Mohammed Atta having been identified as a member of Al Qaeda as early as 2000 reminds the FLUBA Committee on Keeping Anonymous Sources Anonymous, that 'Robert Musil' pretty much had the explanation (back in the Spring of 2002) of what appears to have been curious behavior on the part of the FBI back then, but, in reality, was merely a matter of responding to the perverse incentives put into law by the Church and Pike Committees in the unlamented 1970s.
For instance, from an interview of September 24, 01 with Herbert Rommerstein Musil quotes:
Romerstein: ....Church put in motion a whole series of concepts, that you had to restrict your intelligence services, both your foreign intelligence service, the CIA, and your domestic security, the FBI, because they are the real enemy. They are "rogue elephants," they want to do terrible things to U.S. persons, and you’ve got to stop them.
....In 1979 the Congress passed the Foreign Intelligence Surveillance Act [FISA]. This provided that the FBI had to get a warrant to wiretap somebody they knew to be a foreign intelligence agent or an agent of a "foreign power," ....
....The liberal Democrats decided that this was not a big enough hurdle for the FBI to overcome, so they put up another obstacle to gathering intelligence through wire taps. One of the issues was, "What do you do with Mr. X, who has not engaged in spying in the past or has not engaged in terrorism, but is a member of an organization which has traditionally engaged in espionage or terrorism?" ....the liberal Democrats wanted a provision in the bill that said that you can wiretap only leaders of foreign powers that engage in espionage or terrorism activity, but not the rank and file.
In other words, under the law that passed, the FBI could wiretap bin Laden—if he had been in the United States—but not the guys who took over the airline. They would be considered "rank-and-filers."
[then congressman John] Ashbrook had put in an amendment to cover rank-and-file members of foreign powers or foreign entities, but the chairman of the House Intelligence Committee, Eddie Boland [D.-Mass.], came over to us and said, "John, we’re giving you your amendment. We’re not going to fight it, but just add it to the bill." I said, "John, we won." But John said, "No, we lost, because if we voted on it and got a big enough vote, the House would have to fight for the provision in a Senate-House conference on the bill. But since we didn’t vote on it, they are going to throw it away in conference." And they did.
And so, in the law that eventually passed the Congress, the FBI was unable to wiretap a member of a foreign power engaged in hostile intelligence or terrorism, rank-and-file members of the Soviet controlled Communist Party, for example. ....