One can state many things, but that doesn't mean they have legal effect.
The US Code has provisions for how works become copyrighted
automatically, how they leave copyright automatically at the end of
specific time periods, how some works automatically enter the public
domain on their creation (i.e. works of the US federal government), but
has nothing at all for how a private creator can voluntarily place their
work into the public domain when it would otherwise not be. It used to,
but does not any more.
The case for abandonment was stated as "well settled" in 1998 (Micro-Star
v. Formgen Inc). Unless there has been a major legal change in the years
since then, I don't think it is true that authors cannot abandon
copyright.
For a private individual to say about a work they just created that
"this work is in the Public Domain" is, under US law, merely an
erroneous statement of fact, not a speech act that effects a change in
the legal status of the work. For another example of this distinction,
saying "I am married" when I have not applied for, received, and
solemnified a valid marriage license is just an erroneous statement of
fact and does not make me legally married.
There may be something to what you say, although I think we're now
arguing fine semantic details. See:
https://en.wikipedia.org/wiki/Wikipedia:Granting_work_into_the_public_domain
To play Devil's Advocate in favour of your assertion, it may be that
abandoning copyright does not literally put the work in the public
domain, but merely makes it "quack like the public domain". That is to
say, the author still, in some abstract but legally meaningless sense,
has copyright in the work *but* has given unlimited usage rights. (I
don't actually think that is the case, at least not in the US.)
It's this tiny bit of residual uncertainty that leads some authorities to
say that it is "hard" to release a work into the public domain,
particularly in a world-wide context, and that merely stating "this is in
the public domain" is not sufficient to remove all legal doubt over the
status, and that a more overt and explicit release *may* be required.
Hence the CC0 licence which you refer to. The human readable summary says
in part:
The person who associated a work with this deed has dedicated
the work to the public domain by waiving all of his or her
rights to the work worldwide under copyright law, including
all related and neighboring rights, to the extent allowed by
law.
You can copy, modify, distribute and perform the work, even
for commercial purposes, all without asking permission.
http://creativecommons.org/publicdomain/zero/1.0/
while the actual legal licence comes in at almost 800 words. This is
basically the same as "I release this to the public domain" only longer.
(The CC0 licence is longer than you might expect, because it is assumed
that it may have to apply in countries where you *really cannot*
relinquish copyright. But we're specifically talking about the US, where
the 9th Circuit says you can.)
Relinquishing your rights can have some effect, but not all rights can
be relinquished,
Outside of the US, so-called "moral rights" or "reputation rights" cannot
generally be relinquished, except perhaps in work-for-hire and perhaps
not even then. (E.g. if you're a ghost writer.) The situation in the US
is a bit murky -- there are no official moral rights per se, and
copyright only controls usage rights such as copying, distribution and so
forth. But this doesn't mean that you can (for example) claim authorship
of a public domain work unless you actually wrote it.
In any case, we're discussing copyright, not other rights.
and this is not the same as putting your work into the
public domain.
One might "not be the same" while still being "effectively the same". For
example, the U.S. Copyright Office states that "one may not grant their
work into the public domain. However, a copyright owner may release all
of their rights to their work by stating the work may be freely
reproduced, distributed, etc." as if it were in in the public domain.
But note that the Copyright Office does not make the final decision
whether you can relinquish copyright or not. That's up to the courts.
Among other things, your heirs can sometimes reclaim
those rights in some circumstances if you are not careful (and if they
are valuable enough to bother reclaiming).
That's a good point. A simplistic "I release this to the public domain"
statement *may* (I emphasise the uncertainty) leave some doubt that it is
*sufficiently overt* to prevent your heirs from disagreeing and coming
after your users for infringement. Then the courts have to get involved,
and it's all ugliness and only the lawyers win.
Hence the advice to be as explicit and overt as possible.
If you wish to do something like this, I highly recommend (though IANAL
and TINLA) using the CC0 Waiver from Creative Commons. It has thorough
legalese for relinquishing all the rights that one can relinquish for
the maximum terms that one can do so in as many jurisdictions as
possible and acts as a license to use/distribute/etc. without
restriction even if some rights cannot be relinquished.
I agree with all of that not-legal-advice. And I too am not a lawyer.
Even if US law
were to change to provide for dedicating works to the public domain,
This I disagree with -- the 9th Circuit Court says the US already
provides for that.
What we don't disagree with is that it *may* be trickier than a naive non-
lawyer (including me!) thinks to satisfy the Court's "overt act" test.
Given that uncertainty, overkill may be safer than underkill. The CC0
licence, at nearly 800 words, is probably overkill for the US, but it's
more certain.
I would probably still use the CC0 anyways to account for the high
variability in how different jurisdictions around the world treat their
own public domains.
Yes to all that.