No, there may be something on FR but not that I have seen. Such would not surprise me at all though.
(You may want to search google or dogpile with all the words: terrorists,infiltrated, CIA, and freerepublic)
We do however have stories that show the CIA and FBI ignored warnings including:
An Iranian man living in Germany who tried his best and managed to call both the White House and the CIA to warn them of an imminent attack.
And THe French Secret Service warned the USA of evidence of serious threats of an attack. However again the US Government decided not to do anything to go after the people, investigate the matter or to warn airport security or tighten airport security. There are rerports that some important brass at the Pentagon was warned the day before and canceled plane trips.
Also there is plenty of evidence that the FBI knew that bin Laden had heavy ties to Boston and no actions were taken to shut down or deport anyone there tied to terrorist groups or bin Laden.
Please read all of my threads since the bombing.