Have to expect a few conspiracy theories designed to explain this.
Why? China has been counterfeiting everything the US produces for years, so why should its cash be any different?
LeGaulois answered one of the main reasons why there could be conspiracy theories surrounding this. Flooding a nation with counterfeit bills in an attempt to collapse its economy has been attempted in the past as a form of warfare.
You can collapse a country's economy with this. It's considered as a major crime in my country, you can be jailed for up to 30 years, much more than if you had killed a child. And the motivation is a lot different than your counterfeit nike, it's not for the sake to make money.
People lose confidence in the currency and no longer accept it, companies can't trade anymore because their partners don't want to deal with them, banks refuse to lend money to countries and so on, it's a snowball effect. And I remember to read that just 1% is enough
Hitler used this method during world war 2 as a politico-military weapon (
Operation Bernhard). He wanted to see the British economy collapsing so he created fake GBP notes in order to lower the value of its currency...
The UK did it too during the American Revolutionary War. Hungary, Germany, and Austria participated in a similar operation against France.
It could be the same case regarding China if 900k US banknotes have been found, who knows what haven't been?
Here's a youtube summary of Nazi Germany's Operation Bernhard I saw awhile ago, for those who prefer video clips to reading:
https://www.youtube.com/watch?v=ey0Q-DPMgQUWith counterfeit bills, the concern isn't necessarily with what you see. But rather what you don't. $900,000 in countefeit could represent the tip of an iceberg with far more worrying sums & volumes going undetected.
As far as I know, amateur counterfeiters whose primary motive is greed or profit duplicate larger denominations of money. They would prefer to have counterfeit $10, $50, $100.
Counterfeiting $1 dollar bills could imply the motive is for the counterfeiting op to go undetected for as long as possible. Which could mean it is a large scale attempt to collapse the US economy or wage economic/financial warfare. Or that there is some other strategy or motive in play.
Also for those who say fiat money has an advantage in terms of it not being vulnerable to 51% attacks. Counterfeit cash could be their 51%.