Read-Write Culture, Copyright, and You

One phrase I have been reconsidering lately: "Intellectual Property", and maybe even "Artistic License". They're vaguely synonymous, right?
Since we watched Larry Lessig's TED talk on Creativity and Copyright Laws in class, I've thought about what it means to own something that is available on the internet. If somebody takes your 'work' or property and distributes it in it's original form, then what rights should the original owner have over it? I'm not even sure. It feels as if the 'professional' circles that generate media should be subject to the idea of 'fair use'; but as the same time when an amateur's work is used 'with permission' for commercial purposes, it feels equally wrong and if you look at it this way, the logical ( but not necessarily satisfactory) conclusion is mutual exlcusion. in short, i don't really know which side to join.
back in 2007 when the internet meme, or fad, known as "rickrolling" came into popularity, there was much talk about whether or not Rick astley, the original artist of the song, might release remixes or some other ploy with which to seek a profit from the revival of popularity of his song. he had this to say about it in an interview with the la times:

“I don’t really know whether I want to be doing that[cash in on Rickrolling],” he said. “ I’m not being an ageist, but it’s almost a young person’s thing, that.”