get 5 lawyers in a room.
each lawyer is working for a different client.
each client has a vested interested in the answer to a question.
now ask the question.
you'll get at least 5 differing opinions - each based on the outcome desired by the clients.
a lawyer who makes his living filing cases on behalf of copyright holders will have armed himself with an arsenal of cases references and interpretations that support his arguments on behalf of his clients.
a lawyer who makes his living defending the accused will have his own quiver of legal arrows.
the judge will sift through all the legalize and gobbledygook and use tests and standards of reasonableness as the basis of his ruling.
i'm very happy to see that everyone is conscientious and does not want to break a law or deprive professional designers of rightful income. but, seriously, most of the worry is unneccessary. the rules of thumb are so simple:
(1) if you didn't design it, don't say you did. give credit where it's due.
(2) if you didn't create and publish the pattern, don't pass out copies of it. tell your friends where they can get their own.
(3) don't pass out copies of pages from books or magazines. tell your friends where they can get their own.
(4) if you want to enter something into a show, check the rules of that show and follow them.
(5) put yourself in the shoes of the person trying to make an honest living from her talents.
(6) if you want to go professional, invest some time in research. it will be your most valuable tool.
remember The Golden Rule and act accordingly.
see? easy peezy. ;-)