I was thinking today that this story is an object lesson in how utterly useless the color-coded terror warning system is. Major plot, Al Qaeda cell, hundreds of FBI agents scrambling, no arrests made or bomb materials yet found, and more raids on the way. If this isn’t a code red, nothing is.

Note well: So convinced were the feds that these guys are dangerous that they had their hostage team in the city, ready for action in case the raids turned ugly.

The FBI’s elite Hostage Rescue Team arrived in New York in anticipation of the offensive to thwart a Denver-based terror cell with ties to Al Qaeda, police sources told the Daily News.

Another source said an earlier raid uncovered nine backpacks and cell phones, raising memories of the March 2004 bombings in Madrid…

Najibullah Zazi, the Colorado man who triggered a rash of Queens raids Monday, was identified through e-mail, wire taps and a confidential informant as part of the plot, the source said…

Zazi was stopped at the George Washington Bridge on his way into the city, sources told The News. Authorities later seized his rental car from a Queens street, sources said.

In the car, sources said the feds found documents and papers about bomb-making and bombs.

The Daily News claims the cell is comprised of five men but I don’t know how that squares with the detail about nine backpacks. In fact, if you believe ABC News, it was actually 14 backpacks that were found. Remember: It only took four to kill 52 people in the London bombings of 2005. Exit question: Do they really not have enough to arrest Zazi? E-mails and wiretaps and an informant and bomb-making instructions and a cross-country drive to NYC: Seems like there’s a conspiracy and an overt act in there somewhere. Maybe they let him go in hopes that he’ll do something stupid like contacting other members of the cell, against whom the evidence might momentarily be weak. If you want to see him wearing a sh*t-eating grin and denying everything, follow the ABC link and watch the embedded video.