The right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated, and no Warrants shall issue, but upon probable cause, supported by Oath or affirmation, and particularly describing the place to be searched, and the persons or things to be seized.
-US Constitution
In the formerly constitutional republic called the United States, the above is a part of the sovereign legal document of the land. Every law, rule, whatever made by a state agency or agent must conform to that law or it is null and void. In a trend that has accelerated since 2016, the agents of the state have disregarded various so-called "protections" in their quest for total control. The latest example being the current proposal to have banks report to the IRS any transaction of $600 or more. Those who regularly move relatively large amounts of money are already aware that banks are currently required to report any transaction of 10k or more. You know, to keep the money launderers at bay.
This was actually a significant intrusion into the 4th amendment. They just made a "it' reasonable" argument to get around it. Why? because most citizens do not carry, much less regularly deposit 10k. So they could be convinced that someone who does so could "reasonably" be thought to be committing a crime. And of course "if you're not doing anything illegal then what do you have to hide?"
This last point is regularly trotted out whenever these types want to further encroach on your right to be free of government surveillance. Alas, Americans used to understand WHY we limit government but no longer.
Now having taken that "inch" they are going for the full mile and now everyone is a "suspect" in the supposed crime of "tax-evasion" and so the state needs to search and seize, if they deem your transaction to be in violation of some law somewhere, your assets.
See that "report 10k" was just "putting the tip in" to see how you'd react.
In case you need to know, the way this is supposed to work is that if the government thinks you are committing some crime, in this case tax evasion, it would have to get a warrant. It would have to go to a court and show probable cause to get that warrant and if it got it, it could then search your records and whatever else the court approved of.
The other thing the IRS does is an audit. An audit doesn't get your info though. It takes the info you gave and challenges it. There is no compelling a third party to report on you (snitch culture).
As a side note, this is why everyone should have had a problem with NYS going after Trump's tax documents. Whether you like the man or not, there is a huge danger when the state can target a person (a sitting president no less) in order to *find* a crime to charge him with. Again, the way this is supposed to go is that there is probable cause to suspect a person of a crime. "I don't like Trump's policies" is not probable cause.
So this clear attempt to bypass the 4th here will not stop at the banks. Once enacted, the precedent will be set (which already happened but the bar is being dropped) and other previously out of bounds areas of people activity are next.
Lastly, I want to point out that one way these people are operating is that they will enact a law they know is illegal. They know that it usually takes years for the court cases to go through the courts. Also, that assumes the target person or population even has the financial means to pursue such a case, which they often don't. Even if they lose the case years after the rule was put into place, they get the effect they want.
It is all on purpose and by design.