Great point. I should have been more specific.
Let me add.
after getting explicit written confirmation that that item was legal from the relevant regulatory agency.
(Thankew).
There's no constraint upon legislators or regulators equivalent to "stare decisis"
(which is merely one of a number of competing policies of legal interpretation -
not a binding law).
As long as a statute or regulation has been enacted according to
the actual rules of lawmaking covering a government body
(such as hearings, votes, the ability to pass an appropriate level of judicial scrutiny)
the people have no systemic protection against flip-flops.
Look at the Mass. legislature flip-flopping on
who gets to appoint a replacement for a US Senator,
based entirely on whether the governor is GOP or a Donk.
And lets get serious. Drugs are a consumable. Guns are a capital item. They last forever and are regulated.
Think cars, machinery. Imagine if the EPA suddenly said that all gas powered cars were illegal and needed to be destroyed with no compensation.
How about if a government outlawed possession of video gambling machines?
South Carolina did that, and their Supreme Court said it was a legit exercise of
Police Power, with no need to compensate owners for their (now-) contraband:
Westside Quik Shop Inc v. Stewart
(Closer to your heart?), a CT white paper on whether grandfathering and/or
compensation is necessary for an assault weapons ban:
Assault Weapons Ban and Takings Clause
Lots of the results to the few Google queries I tried
thought I was asking about Civil Forfeiture.
More than one goober has sold their house or business for cash on one coast,
starts driving across country, and some dumbass sheriff's deputy in flyover country
grabs all 5-6 figures to use for a down payment on a new Bearcat
for his department, "because Interstates are used by drug traffickers".
And finally, in the footnotes of uncompensated confiscations
in a frigging (Gabby) Giffords Law Center paper:
The Takings Clause: Not An Obstacle To Smart Gun Laws,
one of the examples is a law against
pit bulls.
If you think your head explodes at the thought of gun confiscations,
imagine a hardcore NES dog-lover's pet being taken without compensation,
and put down by the gummint.
One can debate what laws are equitable, fair, or sensible;
or what laws are so egregious that their passage would constitute Go Time.
Just don't imagine that rises to the level of what laws are constitutional, sigh.