Here we go again.
1. TSA screeners are always "looking for dangerous items", even if they don't find any. Giving them scope to "discover" cash when they're "looking for dangerous items" is simply allowing them to look for cash whenever they choose.

2. Apart from the repeated insistence from TSA screeners that they "have to" inform LEOs about large amounts of cash, what legal requirement is there for TSA to get involved in cash declaration? Cite source, please.

3. Francine dodged it - would you care to give a definition of "large amount" of cash? I assume it's by volume, not value, since you determine whether it's large enough to "investigate" before you count it.

4. If the passenger is on a domestic flight, there are no rules about transporting cash. None. At all. Therefore on domestic flights, there is no way to check whether "rules" have been followed if there are no rules. There is quite simply nothing that TSA or LEOs need to be involved in when a passenger is carrying cash on a domestic flight.

5. If the passenger is on an international flight, it is possible (as has been pointed out here and on PV many times) for the passenger to have made a declaration of the cash by mail on the way to the airport or to be planning to make a declaration before boarding for his international flight. How would a LEO "investigate" whether the rules have been followed?

This is just mission creep and self-importance on the part of TSA screeners. If they want to do CBP's job, they should go get a job at CBP. In the meantime, if they're not busy enough looking for weapons or explosives, they can start screening cargo or go clean some tubs.