Thanks. In fact, given the nature of bitcoin, I would have thought that there might be even greater scrutiny of cash for bitcoin transactions than for a regular bank.
I would worry less about reporting a find to authorities, than being found by whoever “lost” a million bucks in a suitcase. I doubt even a casual stroll across the border into Mexico and ducking into inconspicuous village life (avoid expat colonies) would be safe.
Back to topic: Can the US recall certain notes? Sure. Would druglords be much bothered? I doubt it. They’ll find other ways to buy politicians, courts, cops, businesses. “Plata o plomo” is a difficult offer to refuse.
Yes. Do the drug lords really have all their earnings in palettes of $100 bills, like Breaking Bad? I suspect they’ve found ways to legitimize and convert past earnings already, and even an outright ban on $100 bills would only be a minor inconvenience.
If you are trying to use that hypothetical $1M suitcase of cash, pretty much any action except using it for routine expenses and a few reasonable smaller purchases could come be seen as illegal “structuring”, breaking up cash transactions into smaller amounts to avoid reporting limits.
In my earlier post I pointed out how different money laundering is for small time people (like Walter White) and big organizations. The latter can take suitcases into friendly banks and get the money deposited with nothing reported to the Feds. Bribery and threats are very effective in avoiding paper work.
The Feds have gotten better at detecting this in domestic banks. But there’s a lot of overseas banks that will have personal all too happy to bend the rules, if there are any pertinent rules at all.
Not in America. And overseas, those nations could be blacklisted, so things are tightening up there also. Not to mention, you cant fly with a couple duffle bags of cash.
You do understand I was talking about large, wealthy, criminal organizations here, right? If you can move drugs across borders, cash is no harder. Esp. when you’re moving things out of the US rather than in.
And such organizations tend to find ways around laws and not lose a bit of sleep.
As the Panama Papers proved, the regulations on banks are not exactly enforced 100% of the time.
I read a while ago that well-publicised seizures of large quantities of drugs are much less of a problem for “criminal organizations” than seizures of their cash. There is an almost endless supply of relatively cheap drugs, while cash is more limited, is bulky and attracts a good deal of attention from the authorities.
The border between the USA and Mexico is pretty porous. You can walk.
Now try walking that bag of cash to Switzerland or some island.
Walk or drive south, no problem, not immediately, not if you avoid attracting attention. I’ve repeatedly walked and driven across several Arizona-Sonora crossings. Nobody cares what you walk in. Driving, be sure to buy car insurance at the border, and don’t antagonize the checkpoint guards a dozen miles past the frontier. But they’re mostly looking for firearms. Bury your greenbacks in dirty laundry to avoid discovery. 
No, really. Driving across Mexico in an old SUV, we shower-laundered our clothes in posadas every night, then spread them out to dry on a blanket atop our luggage in the SUV’s rear on the next day’s drive. Checkpoint guards never dug past the top layer.
I’m unfamiliar with Swiss border checks but I’d strenuously avoid likely inspections.
I seriously doubt that this would be the preferred method of moving cash for a drug cartel.
Remember, just because there are laws against speeding doesn’t mean that no one speeds. And that there are laws, border controls, bank rules, etc. against laundering cash doesn’t mean cash isn’t being laundered in the millions every day.
Tell me how you walk from Mexico or Columbia to Switzerland .
A pair of floating Jeezus feet, motorized of course.
On trips overseas over the last decade, it was recommended for countries like Egypt and Tanzania that while the locals appreciate gratuities in American bills (not coin!) that bills earlier than 2003 were not really useful and in fact even newer bills were better. I suppose the other issue with overseas dollars is the prevalence of counterfeit bills. In response, the US has progressively added features that make bills harder to fake.
You can tell the countries with stronger, more reliable (trusted?) currencies. India, for example, had much less reliance on US cash and the locals were happy with their country’s currency. Egypt when we were there was finishing some serious unrest and confidence in the government and the on-going value of local currency was low. (With good reason - apparently it takes about twice as many Egyptian pounds to buy $1US than when we were there.)
Another advantage with US money overseas - there are still $1 bills. IIRC the smallest Euro bill is a five. Translated into local currency, that’s a big difference, giving a local a $1 tip vs. about $8.