Feds: Al Qaeda Mata Hari Wanted To Poison Pres. Carter

Those e-mails, a source involved in the investigation said, are between "what she described as 'units' and what we would call 'cells'."

That haul of information has led multiple government sources to describe Siddique as a potential "treasure trove" of information on terrorist supporters, sympathizers or "sleepers" in the United States and overseas.

"She is the most significant capture in five years," said former CIA officer John Kiriakou, who said she lives up to her reputation as an alleged terrorist 'Mata Hari.'

And there is an eagerness to see what, if anything, she can add to the thin trickle of fresh information on the activities of terrorists and terrorist supporters in Afghanistan and Pakistan as well as what if any risk she might pose to national security.

"She is a very dangerous person, no doubt about it," said a senior US counter terrorism official.

"This is a major haul, a major capture for the FBI," said Kiriakou. "To find someone who has such rich information—computer hard drives, e-mails—that's really a major capture."

New York Senator Hillary Clinton released a statement Wednesady.

"Today's revelation that suspected terrorist Aafia Siddique was apprehended carrying a list of potential attack sites including a number of New York landmarks is a sobering reminder that New York remains a top target for terrorist attack," said Clinton.

"Federal agencies and law enforcement officials must continue to be on alert and work together to keep our nation safe. It is critical that we remain vigilant in confronting these threats here at home and abroad. It further underscores the need for the Department of Homeland Security to allocate the necessary funds to protect New York and its residents. I will continue fight to ensure that New York has the tools and resources needed to continue the fight against terrorism," she wrote.

Click Here for the Investigative Homepage.