Bootlegs of scandinavian porn sold legally in the USA ?

[Caroline-NL]

Several scandinavian companies complained about the selling
of bootlegs in the USA. These so-called "public domain companies" stated:

" Are these illegal bootlegs ? Definitely not! The section of American copyright law known as "The Berne Act" clearly states: films unreleased in the United States, including original version of films altered and/or edited for release in the United States, are not protected by American copyright; thus, they are considered public domain."

Is this really true ? For material produced prior 1975, yes, but not for later material, or ?
I cant copy an old US movie in Europe, even if this isnt released here.
Wasnt there a "Copyright Re-Registration Act" in the late 90s, also copyrighting european movies, that were in the public domain, because they were produced before 1975 ?