Can you legaly share a course (without asking the writer) if you always quote who wrote it?
I said "always" because I'm talking about a large scale, not a private conversation on Facebook for example.
Does it have something to do with money? I understand selling someone's work is not ok, but what about money generated by discret publicity?
What about public domain knowledge? How do you make a legal difference between sharing Thales Theorem and sharing a formula found by one of your teachers? Between sharing a quote from a famous person with a not famous person? Is it related to 'is the person alive'?