I have looked over this site several times as I have been a victim of polygraphs and CVSA. I figured I'd share this today as I had an experience this morning watching officers from an agency I had an offer from carrying out their duty. 
I have received 3 offers from different law enforcement agencies, this is after I even put my self therough an academy on my dime. 
The one agency was just waiting to get me a start date as I passed all the background check stages with flying colors. Then came the poly and they told me I "showed a reaction to drug questions." This was a shock to me as I don't even use over the counter medication and am a big proponent of natural health. After the examiner grilled me through a bad TV style interrogation I got a rejection despite passing everything else.   

I recently got another offer from another agency that in order to finalize I had to resign my current job. I was fine doing this because I had 3 active law enforcement officers vouching for me and was told from someone at the agency that he was told by the hiring staff that I was the only one in contention for the job. Then comes the CVSA. This time I pass the drug question but was instead told I was deceptive about domestic violence of all things. And with that my "sure thing" job was gone. 

The poly and CVSA have effectively ruined my life. It has left me without a job, having lost two jobs I had formal offers for, cost me my dream that I have worked towards for years. And despite all that the worst part is after trying hard to lead a good clean life these bullsh*t machines are branding me a drug abusing wife beater. Nothing like carrying that around when trying to get a job.

What is it worth to lead a good life, stay out of trouble, do all the work to deserve what you want to be, yet flawed machine holds your fate.
In a final irony I've had poly examiners look down on the fact that I don't drink, smoke, or do drugs and I must be hiding something.