'High tempo' of terrorist chatter: FBI


WASHINGTON - The FBI has increased its use of secret search warrants over the past two years because of a "high tempo of terrorist activity," a top official said yesterday.

FBI Assistant Director John Miller said the 2,176 Foreign Intelligence Surveillance Act search warrants approved last year, compared with only 1,754 granted in 2005, mostly targeted plotters inside America.

"We're seeing a very high tempo of terrorist activity, not just based on the cases you're seeing being brought in the United States," Miller said in an interview yesterday for C-SPAN's "Newsmaker" program.

Miller said the warrants, issued by a secret federal court in Washington, are usually not a "way to a prosecution," but are "an intelligence tool."

The FBI's chief spokesman - who as a TV newsman conducted a 1998 interview with Osama Bin Laden - echoed other counterterror officials who say the U.S. may have underestimated top Al Qaeda leaders' ability to oversee operations in recent years.

One measure is the record-high output of video and audio messages from Bin Laden and his deputy Ayman al-Zawahiri.

Typically there has been "a two-year arc between major attacks to develop the plan and execute it," Miller said.

Al Qaeda is "on a bell curve and they're getting more effective" at planning new strikes while pushing propaganda to inspire others to "take that ball and run with it."

"They're counting on both happening at once," Miller said. "They're better at this than they were before and they're thinking about it differently."

jmeek@nydailynews.com