And I've carried just under $10k for transactions but nervously looked over my shoulder, not for thieves but for government DEA jerks intent on stealing citizens' money. A paper trail won't save you, because you'll lose in lawyer's fees and loss of money while fighting to get it back. Ordinary citizens are victimized while Mexican drug lords get away with murder (literally).
Mentioned before, here, a Georgia judge returned $300,000 taped to a Columbian’s body aboard a jetliner. I had reported him to the pilot, as he appeared suspivious—and suspected a hijacking—popular at the time.
Attendents related a drug deal concluded during the flight to the judge. Mid-80s, I’m guessing.