Well, the system did work, sort of. But not much good to question someone when they get off the plane if the person in question is going to blow up the plane:

Reporting from Washington - U.S. border security officials learned of the alleged extremist links of the suspect in the Christmas Day jetliner bombing attempt as he was airborne from Amsterdam to Detroit and had decided to question him when he landed, officials disclosed Wednesday.

The new information shows that border enforcement officials discovered the suspected extremist ties involving the Nigerian, Umar Farouk Abdulmutallab, in a database despite intelligence failures that have been criticized by President Obama.

"The people in Detroit were prepared to look at him in secondary inspection," a senior law enforcement official said. "The decision had been made. The [database] had picked up the State Department concern about this guy -- that this guy may have been involved with extremist elements in Yemen."

If the intelligence had been detected sooner, it could have resulted in the interrogation and search of Abdulmutallab at the airport in Amsterdam, according to senior law enforcement officials, all of whom requested anonymity because of the sensitivity of the case.

"They could have made the decision on whether to stop him from getting on the plane," the senior law enforcement official said.

But an administration official said late Wednesday that the information would not have resulted in further scrutiny before the suspect departed. Abdulmutallab was in a database containing half a million names of people with suspected extremist links but who are not considered threats. Therefore, border security officials would have sought only to question him upon arrival in the U.S., the administration official said.