If I were in your shoes, I would withdraw my application to avoid the polygraph. The FBI has a pre-employment polygraph failure rate on the order of 50%. Failing it means a permanent bar to FBI employment and may make it more difficult to obtain a security clearance from other agencies. For more in this regard, see my article, "Just Say 'No' to FBI Polygraphs."

Unfortunately, the "complete honesty" approach (informing the polygrapher that you're familiar with polygraph procedure and countermeasures) is likely to result in an arbitrary accusation of deception and/or countermeasure use. Agencies that continue to rely on the polygraph despite the National Academy of Sciences' finding that "its accuracy in distinguishing actual or potential security violators from innocent test takers is insufficient to justify reliance on its use in employee security screening in federal agencies" find it difficult to abide those honest enough to admit knowing "the lie behind the lie detector."

OK, reading more posts here and am approaching paranioa. Why the hell would they care who I chat with on the internet? Are they really going to ask me if I've cybered with people?? (answer = yes). There is nothing on the background check paperwork about such things...
Also, I was a bit of a klepto as a teenager, how should I disclose that, since questions about theft seem to be guaranteed to come up? I was never caught and of a total PERHAPS 20 thefts I would say a monetary valueof less than 200 dollars.  Breaking out into a cold sweat now.

I am currently in phase 3 of my application to the FBI contract linguist position (I have one language test left to pass) and soon I will have to do the polygraph. I am very nervous about the test and worried about what to do. I have known/believed for quite some time that the polygraph is less than 100% accurate and certain depictions of it in television and movies make me want to scream FOUL! But anyways, after having read several of the threads here, especially Perplexed, I am now VERY VERY nervous. I am currently a college student and my real aspirations are to work for the NSA, should I not continue my application with the FBI? (which I saw principally as a way to get my background check done before graduation next year) or should I proceed with the COMPLETE HONESTY option?