But what constitutes "suspicion/concern" and who is the judge of that? I have in the past routinely traveled SFO-LAS with $10-$15k in cash and to me, based on the destination AND that it is a domestic flight AND where there are no reporting requirements (i.e. FinCen form #104 for international flights), I don't see how and why a TSO would refer this matter to a LEO. Now as to an international flight, I still do not think it falls under the TSA's realm as they (The TSA) are not CBP and it is the job of CBP NOT the TSA to investigate-and with that, If I as a pax properly declare that I am traveling with greater than $10k in currency or currency equivalent to CBP, it's a done deal at that point but if I d do not declare it, it's on me and between me and CBP, not the TSA. The TSA's job regarding pax is to keep prohibited items from entering the secure area to allow only properly identified pax to enter the secure area and that's it