Distinguish ethical from legal. Not all laws are ethical (depending on where you live, most laws could easily be unethical), and this website goes out of its way to say why the laws they violate are not.
>One may well ask: “How can you advocate breaking some laws and obeying others?” The answer is found in the fact that there are two types of laws: There are just laws and there are unjust laws. I would be the first to advocate obeying just laws. One has not only a legal but moral responsibility to obey just laws. Conversely, one has a moral responsibility to disobey unjust laws. I would agree with Saint Augustine that “An unjust law is no law at all.” Now what is the difference between the two? How does one determine when a law is just or unjust?
One guidance for the ethical side are the guidelines agreed upon by professional associations. I can't think of any that condone copyright infringement.
I disagree that that is a good source of guidance. Even if we take that as a given, OF COURSE few organizations promote breaking the law (sometimes a crime it self).
Another guidance for the ethical side is the concrete behaviour of working scientists: If they would send you the paper if you asked them by email, this is a clear statement that copyright violation is perfectly okay.
Way back in the day, we would buy reprints from the journal, and then mail them to requesters. And then Xerox machines appeared, and we made our own copies. Now we just email PDFs.
At least in my discipline, authors either retain copyright to their manuscript and can disseminate that freely, or they are able to personally disseminate the final published article (sometimes including on their own website). No copyright transgression occurs in this case.
-Dr. King, Letter From a Birmingham Jail