From what I hear, a lot of illegals don't trust banks and carry a good deal of their cash around with them.
Back in the summer of 1983, I was working for Metro-North Railroad as a hostler, moving commuter cars around in the Croton-Harmon (NY) shops.
Working one night on the midnight shift, I was in a car scrounging for papers to read (which I would also use for a pillow when the work was done for a while). Just happened to see a wallet lying on one of the seats.
I picked it up, didn't even look in it, and brought it to the foreman's office, and they said they'd handle it.
Turns out that it belonged to one of the hotshot producers on "60 minutes".
Got a letter from the company for that one...