I shared a whopper of an experience when I e-signed the petition.   

Since the time I took the poly and showed the bogus "deception" results, I've told many others of that experience.  In two occasions, I was told return stories of the false positives, and thus the costing of jobs in both incidences (one was an attorney, another, a Naval Officer).

A friend of mine probably stated it best: "If you pass ...well... that doesn't prove anything... but if you fail, that proves everything!!!"  I like that analogy.

Back to the 'subject' line: 
My contention is, that poly operators have to continuously prove their instruments are valuable and give valid results.  If EVER an operator came forward and denied the credibility of the machine, they'd loose their bread & butter profession.

So, what could a polygraph operator do if he wasn't operating a poly??? Not a lot of industry choices there... sounds like a pretty good reason to justify the validity of their equipment... and more scary.... it sounds like a GREAT reason for operators to promote the admissibility of the results into courts... lots more poly traffic and big bucks for them if that ever happens.