My main problems with copyright are that it is a false economy, and that for a lot of media it is not in the interest of people. I'm a student & there's little reason for me to support copyright* - I'm not invested in the system. I own little valuable IP, I expect to create very little, but every day my activities are constrained by copyright law.
"The American people would just have to get over the fact that software no longer had any economic values. It wasn't fair, it wasn't just, but it was a fait accompli. In many ways, Oscar had to give the Chinese credit for their cleverness in making all English language intellectual property available on their nets at no charge. The Chinese hadn't even needed to leave their own borders in order to kick the blocks out from under the American economy." - Bruce Sterling's Distraction.
But it doesn't need to be China to expose the deceptive value of copyright, the twak consortium (or seasteaders) might declare moonbase alpha it's very own sovereign territory and remove copyright. Moonbase alpha can then listen to all of Earth's music without charge, it's a no brainier for those uninvested in copyright.
Massive piracy means that copyright is making most consumers illegal. Piracy is commonplace, trivial and increasingly accidental (copyrighted works in the background of hi res photos, music in the background of a youtube video, buying used software often breaks the EULA). It is becoming very difficult to live a life in which you do not break copyright laws. Perhaps this should be taken as a hint that they aren't compatible with today's technologies.
Industries that rely on copyright have started to look dubious. Print newspapers' revenue is in free fall, the music industry is trying to sue its customers and book publishers are trying to stop computers reading their books aloud. These are not activities that secure, upcoming companies engage in. The companies in these sectors that are doing well, are doing so because they are moving away from a copyright dependent model. Perhaps they're worried that their wealth is based on a bubble? (In the light of current financial problems, it might be unsporting to point out that we're building a bubble around IP that could burst). It could be burst by another country as an act of war or it could be burst by new technology (undetectable music copying?). Overnight our copyrighted material, our copyrighted assets, might be worth as much as the canvas, paper or disk that they're held on. We've added a lot of value to something that isn't tangible, and is making less and less sense every day. If that bubble bursts, lots of value will be dumped from the big companies - it's best we slowly deflate the bubble slowly, rather than wait for the time bomb to explode.
So the main question is how much content wouldn't get published without copyright? And how much broader content would each person experience without copyright? Here's a fun gedankenexperiment:
We only need copyright on things that are expensive to create. On things that wouldn't be created without it. Music is fun to make, people can do it very cheaply in the evenings, and they enjoy it. What about abolishing music copyright? Would the population as a whole suffer? All currently available music would be free to all people - I think the value of this person is more than the value of the record companies. Distribution by the record companies isn't needed, the net is a suitable medium - music is quick and easy to download and many people who like music use portable mp3 players and never see CDs. However the very popular artists with all the money would loose most of their incomes, as would the record companies. But would music continue to exist? yes - we have huge backlogs of material that we mostly don't get access to because of copyright. Would music continue to be made? yes - it's very cheap to create music (you can do it your basement), and more importantly it's so much fun you couldn't stop people creating it if you wanted to.
This is very much a socialist argument. It's benefits wouldn't be measurable in market capitalizations or economic figures, it's benefits would be in the breadth and quality of music people end up listening to every day
Which other arenas is copyright unnecessary in? Photography maybe, but there aren't too many other media with which the above argument holds today, but films and video games are starting to get to the point where they can be made to a comparable quality by people in their bedrooms, for fun. Not for profit feature films include Bloodspell and Star Wreck, although their quality isn't up to it yet, it will one day.
We're just waiting, in all these media, for the quality of the work by people-who-do-it-for-fun to get good enough. It doesn't have to be perfect, it just has to be sufficient, such that 90% of the people don't notice it 90% of the time. As more people get involved in doing it for fun, the quality gets better. You can look at the "most interesting" photos in flickr and the quality is immaculate (a million monkeys with a million Canon 400d's). This is because of the number of people involved, the sophistication of the technology they use, and because it's fun!
Copyright protects the establishment. In a certain way I think it stops people being able to publish their own work. People have been groomed into accepting high production values in their media. What if the established publishing houses disappeared - if the Hollywood studios vaporized?** I might start reading more interesting books and watching a broader range of movies. So much is spent on polish and advertisements that smaller artists are drowned out (do you really think that the profits of an artist correlate with how good their music is?). Social media techniques like digg.com would allow you find what other people think is good, rather than who's paid most for advertising.
Of course this doesn't reach to all areas, copyright in more hi-tech industries still seems to be needed (such as software engineering), until they too can be done entirely in the bedroom. When I can ask a computer "computer, write me a word processing application!" I think the copyright on software should be abolished (and probably patents too, but that's an argument for another day).
But today we have to ask if copyright is still a benefit to the people? It has got to the point where copyright is holding back a tide (academic paper on the subject) of new exciting & valuable content. Copyright prevents derivative works - new content from that which exists. The Grey Album or American Edit are great bits of music that the world will not hear because of copyright. This work cannot take place under copyright law - the people who do it for fun can't afford to use copyrighted materials. Licensing copyrighted media is expensive, time consuming and not much fun at all.
My final point is that we may soon find ourselves in a world where computers can create desirable content unassisted (this is part of my work, finding tools to help (and maybe replace) 3D artists). When a computer can write you a pop song, does copyright make sense?
Copying can't be stopped, as long as I can point a camcorder at the screen of my telly; As long as I view the movie with my eyes and store it in my brain. Copyright just feels broken.
* A land of copyright-haves and have-nots. I own little copyright, I consume huge quantities of copyrighted material. So how much of it would have been written without copyright? What incentive do I have to welcome stronger IP laws?
** can tell I'm trying to be persuasive, I keep using question marks?
*** sorry for the rant. had to be said. yes the blog is copyright. yes I'll put it under CC, but not until next year...
 this is another summary of the issues surrounding copyright: