Why anyone would use BTC and not some privacy coin for this kind of scenario escapes me.

If you read the original DOJ filing, they actually did that. They used :

> anonymity-enhanced virtual currency (AEC), in a practice known as “chain hopping”; and using U.S.-based business accounts to legitimize their banking activity.

Their problem was that they "closed" the money circle by sending it to real bank accounts. That's how they caught their trace. It seems that laundering billions of dollars is not as easy as they thought haha.

Someone was saying they could have moved to South America and laundered $1000 at a time, but you'd think that the US government could've easily tracked that down as well.. "Hmm, it appears someone is living off this stolen 3 billion dollars in South America"

How would you trace $1000 to a larger source after it passes through a privacy coin? The only way to do that is either with some side channel information, or by monitoring the person selling the funds. In a cash economy in the third world the odds of that look pretty poor. I think what happened is large deposit in bank account caused some to start asking questions.

Because they stole bitcoin. Good luck finding a non institutional buyer for tainted bitcoins when you're dealing in billions usd. Everyone shuffling bits at that level is going to play by the rules and cover their ass. Even large criminal exchanges will avoid stolen bitcoin in any sort of volume because it means instant scrutiny.

Even large criminal exchanges outside of US jurisdiction? (ie, Russia, China, etc.)

Is it practical to convert literal billions of dollars between currencies? And even if you did, wouldn't liquidating it so you can actually spend it on things in the real world prove to be almost impossible? Billions of dollars worth of currency is more than I'd expect most privacy coins to deal with over the course of months.

But in this case, accessing the billions in BTC was impossible too, so for all intents and purposes, that number wasn't real, since it wasn't usable.

The question is perhaps what is the most one can use and how to do it. Privacy coins probably play a part in this equation.

You maybe could slowly, and methodically convert it out of the privacy coin into a spendable form when needed.

Laundering within the constraints of a public ledger isn't feasible for long periods of time or large amounts of money - the only way to win that game is to be so small nobody cares.

They could have possibly gotten cash from cartels at a steep discount, but that story would probably have ended with a richer cartel and two dead nerds.

I always wonder how many people won this long con by being so small nobody cares. The DoJ document states they already succeeded in taking the funds cross chain and through some privacy enhancing alternative assets. For every idiot dumping millions in a bank account there's got to be someone else living a "modest" but luxurious life looking like a small guy nobody cares about, cashing out a few hundred to a thousand at a time somewhere where that kind of money is big enough to get a nice day to day living but small enough to not be worth organized crime taking much notice.

On the flip side, most of us could already live quiet, comfortable lives in Thailand or Cambodia on our normal software engineering income.

Maybe these guys are thinking if you're going to be a criminal, you had better make the juice worth the squeeze. Live large, party extravagantly, and probably just rent everything from hotel rooms to yachts so there's less for the authorities to eventually impound when it catches up to you.