When the Securities Exchange Commission decides that something is a security, it retroactively applies the civil and criminal compliance back to 1934 because it was always a security. I mean, you can argue it in front of a judge if you want, but thats how they established jurisdiction.
Same goes for discretionary tax law at the IRS
or any regulatory agency
I agree its a problem, but if you live your life under your version of reality it is easy to get railroaded in the dragnet
New Regulation -> Future Date -> Ex post facto claims don't happen.
That is the process my original comment intended to imply.
If you are a vast major bank and don't like the SEC you can try not being allowed in the doors of the private buildings of the NYSE, LSE etc.
They have the power not of law but of losing billions
That's not a retroactive application of the law. If they are correct in their interpretation of the law, it was already the law. If they are incorrect, the courts will not allow it (whether the enforcement concerns acts before or after the determination by the SEC.)
The ATF is particularly notorious for this.
Yes, and if that conflicts with what the courts believe the law has always meant, those decisions won't survive contact with the legal system. An ex post facto law is a law creating (or enhancing) criminal penalties for acts that exist before the law is passed. Changing administration interpretations are like changing prosecutorial priorities (and the former comes with a lot more notice and specificity than the latter) -- they only have effect so long as they are within the bounds of what the courts will accept was covered by the law when it was passed.
https://en.wikipedia.org/wiki/Chevron_U.S.A.,_Inc._v._Natura....
IANAL though, so I digress.