I made my original post as I stewed at the gate waiting for my delayed flight, but thought I should share more details.......

I was selected for additional screening after my initial pass through the detector. I normally do not pass my wallet through the xray, as I only carry cash, credit cards and my driver's license, so I had it on my person. After I was wanded by the TSA agent, he did the routine pat-down and felt my wallet. He asked that I remove it and put it in one of the plastic containers. I did so without question, thinking he just intended to run it through the xray machine. That is not what happened. He finished up his pat-down and then proceeded to hand over the container with my wallet to his associates. They asked if they could conduct a trace residue test on my items. I assumed they meant my laptop bag and shoes, which is what they originally tested, but this is when they decided to search my wallet. As most of you are aware, they conduct this trace test in a little half desk cubicle sort of thing that blocks most of your sight from what they are doing. I only became aware that my wallet was being searched because the woman going through it dropped half of its contents onto the floor (and no, I do not have a wallet that would just open allowing things to randomly fall out).

Anyway, thank you all for your fast responses. Quite frankly, I just felt a bit intruded on and wanted see if others had any similar experiences. Oh, and by the way, I will take some of the advice shared here should this happen to me again.