Kaestur Hakarl keeps removing my offer to e-mail a copy of Emil Artin's Geometric Algebra to the OP of a question.
What I did is not against the rules, and I ask Kaestur Hakarl to please stop removing the end of my post. Whether or not it will be allowed in the future is up for debate, and if the community decides that offering to e-mail books and papers is against the rules, then so be it. However, that is not yet the case.
So, could the post please be unlocked?
I think it would have been possible for 97832123 to phrase the original message in a way which would have been just as helpful to someone wanting to acquire a copy of Artin's book but without opening up himself and the site to worries about copyright violations.
Sample text: "I have a copy of Artin's Geometric Algebra. Please let me know if you are interested."
As written, perhaps 97832123 has a print copy of the book that he is willing to give, lend or sell to user X. There are other possible, and completely legal, interpretations. It is then none of our business what actually transpires between 97832123 and X.
The timeline of events was roughly:
This is based on memory, not timestamps, so things are the order I saw them rather than the order they actually happened. Someone with a clearer picture can clear up any inaccuracy.
No one should regard 97832123's offer as immoral: Artin has been dead for nearly sixty years, his wife a few years ago, and the copyright renewal occured more than thirty years after his death. Rather, the issue is that the offer is an offer to infringe the law, and at best, puts the site in some slight legal risk.
Wouldn't it be better if 97832123 changed his text to say that he has emailed the PDF in the past, and there's a dispute about his past offer, with a link to this meta qn? Any intelligent person can infer that the offer is likely still to be open, but the offer is no longer advertised on this site. The legal risk to the site becomes negligible, provided this doesn't become a frequently used cipher.
from MO meta-comment by one of the founders:
"I think the consensus among moderators was that we had no interest in enforcing DMCA proactively. We certainly won't take any action in the absence of a takedown notice from the owner of the material, and I think even then the sense was that that was an issue from whoever was hosting the material, not MathOverflow as a site."
http://tea.mathoverflow.net/discussion/313/when-a-paper-is-behind-a-paywall/
This is more of a comment than an answer, but my guess is that this will be less of an issue on this website than on MO, because while a lot of technical material in mathematics is basically available only as (usually copyrighted) books, most of the material discussed here is canonical enough to be available (legally) on the internet (if a reference is necessary).
For what it's worth, though, MO is fairly liberal in allowing links to copyrighted material. I would not call for their deletion on this website either, in the small number of cases where they do occur. The main problem I saw was that the comment thread was turning into an argument of the merits of copyright law.
If there is no clear community consent on something being allowed, moderators are well within their rights to restrict it from appearing. If we don't trust them with this power, then we shouldn't elect them as moderators. If there is a controversy about the moderators decision, they are well within their rights to restrict it until the controversy is resolved. If no clear community consent is formed, then the moderators should form their own consent on which policy is the best default at least until the time that community figures out the issue. Moderators need these powers in order to probably protect our community.
I think of my position as conservative - moderators should have powers unless the community think that they shouldn't have that power, but also, moderators shouldn't use those powers unless they have to use those powers.
Offering to email books or papers in the public domain or any that you have legal right to distribute (e.g. you are the author) is perfectly fine. This is not the case for the book in question. Please see this brief reference on US copyright.
Artin's Geometric Algebra was originally copyrighted in 1957 (registration number A00000271595) and was renewed in 1985 (registration number RE0000275074). As such, it will take until 2052 before distribution of this book without permission of Emil Artin's publishers or heirs will be legal here.
While the above refers only to US copyright law, the user who originally flagged the post mentioned that the same would apply in Germany (and I'm sure, in a few other countries as well). I will also note that while the legal policy of math.stackexchange does not obligate moderators to remove such an offer from the site, I can not in good conscience leave up any illegal material I am made aware of.
Copyright aside, offering to email a copy of a book adds no value to the site. Offering the name of the book and page number is fine, but summarizing the content and putting it here would be even better. We want the site to be as self-contained as possible. That's why I felt that my edit removed nothing of value.
I had reason to believe from this user's comments on the answer about his stance on copyright law and piracy that leaving a comment asking him to change his post would have no effect. Thus I edited the post myself, and when he attempted to revert it, locked it.
As for whether I made a mistake in not making a meta thread first, that's certainly possible. It simply never occurred to me that removing an offer to distribute an illegal copy of another mathematician's copyrighted work would be controversial enough (beyond 97832123 himself, whose attitudes towards copyright law and piracy were clearly given in the comments on that answer, then deleted by someone other than me) to warrant a meta topic. However, that meta topic has now been created. Further discussion of general policy towards copyright infringement should go there.
