NEVER try to go through the pat down with wallet!!
The one time I tried to keep my wallet with me, I had already put everything else through the xray machine and was stepping up to the physical search when they THEN insisted the wallet in my pocket HAD to go through XRAY or they would not do the physical search. THAT left me with no choice but to put the wallet through BY ITSELF (too late to put it in anything else) and while they "patted me" (averting my view of the wallet) the TSA lightened my wallet of a considerable amount BUT NOT ALL my cash. Seeing SOME money in my wallet, it was a few minutes later before I counted it and realized they had tapped it of a hunk of cash. I think it is a TEAM effort in thievery, as they deliberately stand so you have to look away from the xray table to talk and deal with them.