This has been going on forever.
I don't know if the DEA still does this, but they used to ROUTINELY arrest and take money from people carrying what they considered "excessive" amounts of cash in airports.
How did they know?
Some people pay for their tickets and flash a roll when paying. Ticket clerks were paid a "finders fee" to turn in passengers.
The victim would then have to sue to get his money back and prove that he earned it through legal means and was not involved in the drug business.
"Are you surprised that this happened?"
Not at all.
Insight on how to respond to "fishing expedition" type questions from the so called authorities.
Click here to see a very informative video by a US Law Professor who explains - Why you should never answer questions you are not legally required to answer