Here's an ironic story as to how much the FBI "trusts" the polygraph:

According to the 9-11 commission, an Al-Quadia member confessed in April 2000 that he had been trained to hijack an Airplane as part of a terrorist plot.  He was administered two polygraphs, and according to the report, "passed" each, but the FBI still didn't believe him.   

So let me see if I understand the logic here.  It's OK to not to hire people who "fail" the polygraph, yet have had the background checks completed but at the same time it's also acceptable to not investigate potential terrorsits even though they "pass" the polygraph?  Which is it?  Either the polygraph is the "golden bullet- all knowing machine" that it's supporters claim, or it's a worthless piece of crap.  If it was all that so many of its supporters claim, then why wasn't the fact that the Al-Quadia member "passed" two polygrpahs enough to justify a more detalied look into his accusations?  Personally, I think it's because it's well known that the polygraph is just not reliable!

BTW, here's an excerpt to the story, which is at www.msnbc.com:

The most significant signal appears to have come in April 2000, when Niaz Khan, a Briton of Pakistani heritage, walked into the FBI’s office in Newark, N.J.

Khan told agents that he had been trained by al-Qaida, the terrorist network that carried out the Sept. 11 attacks, and that there would be a hijacking in the United States or on a U.S. airline.

He said he had been sent to the United States to join al-Qaida operatives here. Even though he passed two polygraph tests, FBI headquarters did not believe him and let him go.
“I told them before the 9/11 — more than a year” ahead of time, Khan told NBC News. 


Here's the full link to the story:
http://www.msnbc.msn.com/id/5456067/