release as public domain, which means completely unencumbered and free
In general, this is true, but some countries do not have a concept of public domain and so releasing it into the public domain would make it completely unusable to people in those countries. Personally, I would prefer either the BSD or MIT license or something like the WTFPL[1].
I mean, suppose a user in Nopublicdomainistan uses some software that is released in the public domain... clearly the author is never going to come after them for a copyright violation, even if their local government doesn't recognize public domain as a concept, so what is the actual real world problem they face in this situation?
I just don't see this as being a real problem.
I don't know of any countries that do not recognise public domain as a concept, but there are many countries (including the USA) whose copyright laws have no provision for an author 'giving up' their copyright. Just saying "I release this into the public domain" does not necessarily do that, any more than walking away from a house you own means you no longer own it. That means that if somebody says "I release this into the public domain", there's no reason why they couldn't change their mind and sue you for infringing their copyright later.
For more information, see this FAQ on public domain: http://linuxmafia.com/faq/Licensing_and_Law/public-domain.ht...
Also note that Creative Commons has a special "Creative Commons Zero" license designed to provide the same results as "I release this into the public domain" in all jurisdictions, and it takes at least a page of legalese to do so: http://creativecommons.org/choose/zero/
TL;DR: saying "I release this into the public domain" probably doesn't do anything; just slap a BSD, MIT or ISC license on the work instead.
The problem isn't that your might get sued, it's that you can't convince $POINTY_HAIRED_BOSS that you won't get sued.
I still think the original objection is more retold fairy tale than truth, but if anyone wants to prove me wrong they can point me to a country where public domain isn't recognized, but random user-written OSS licenses are and the country has any sort of culture of respecting copyright in the first place.
Anyone said Germany? The concept of the "Urheberrecht" which many people falsly translate to copyright (it's more of a creator-right) is that you can not relinquish it in Germany. It's kinda like your mother can not "un-mother" herself from you ;)
That's why there's no real Public Domain in its purest form possible in Germany.
> clearly the author is never going to come after them. so what is the actual real world problem they face in this situation
The real problem is: A lack of legal certainty. You can not use PD in any bigger project if it is _possible_ that the original author might come after you.
There is also another problem, you can't disclaim some warranties for customers. So if you could release the software into the public domain, you could still be held accountable for what the software did after being modified.
</nitpicking>
I've heard this in the past. Functionally, what's the issue with this? The person who placed it into the public domain seems unlikely to sue in a country that doesn't recognize the public domain status.
http://linuxmafia.com/faq/Licensing_and_Law/public-domain.ht...