Just exactly a month ago they stole the Bic lighter out of my camera bag (like maybe I was gonna go big and take down a DH-8 turboprop - somehow, with that). The same lighter made it from Eugene to Puerto Vallarta and back. Guess I should have put it in my pocket. But no worry - I had no more use for it then until I got home - and just in case, I still had plenty of matches.
I used to work for that agency. I resigned after 2 years basically in disgust for this type of activity as well as other things.
Most likely they didn't steal your lighter. It was a prohibited item per their regs at least at that time. They should have left a note in the bag. As far as the lighter getting thru other airports , it probably was just missed.
IMHO the primary reason this case came to light was the victims were mainly celebrities with high visibility and high end items. The TSA couldn't sweep the thefts under the rug. Ordinary people probably wouldn't have received the same attention, sad to say.
I was half joking. They didn't snitch it, they found it in the carry on and told me it was prohibited and offered to "throw it away" for me (bet the TSA folks don't ever have to buy stuff like that - but big deal, 99 cents and probably 2/3 used up). But when I began the trip five days earlier and first boarded in Eugene, it wasn't (or maybe they just didn't care that I had it there). Point is, they are inconsistent. Second point is matches appear to be OK. Third point is, a pocketed disposable lighter would most likely walk right through the metal detector.
But I can see the problem with checked bags and lack of visibility of the inspection crews. In the Eugene airport (a very small airport) the baggage inspection area is right up front. You go to check in and get them tagged, then carry them yourself to the TSA inspection area which is in the open in the main lobby area, and they feed them on a short belt through an imaging device and that's it. From there they are taken by the airlines' privately employed handlers right to the planes. That scenario probably wouldn't be practical at large airports though. Most luggage has false bottoms, and I figure valuables are relatively safe there.