I don't believe in intellectual property. The analogy is nonsense. Still, anyone with a slightly practical mind can see that authors and makers of works need some manner of authority over it. But that's precisely it: they need authority, not ownership. Ownership is one form of authority, and rather an extreme one.
Just as with contracts concerning labor, there should be limits on the gains you can demand of an idea. You can argue that it may, at times, be in an artist's best interests fully to vest his work to a corporation; the fact is, it's irrelevent. The difference between that and a less restrictive contract is so minute as regards gains and so vast as regards losses that the only reason to allow it is to encourage swindlers.
Shall I let you make a movie of my book? Fine. Shall I let you make all the movies you want from my books? Fine, I guess. Shall I let you make movies of my books and keep me from using my books elsewhere? For a time, but there must be a sunset. I can contract myself to a company for a six month fishing voyage, but if they want my entire life on one signature we've got a constitutional problem. I think it's rather the same.
And music and movies on computers? I still believe that people want to pay for music, but they want to be able to share it, too. They don't want DRM (if they know what that means). I really do believe that people would give money to artists if they were given the ability. And I think that recordings are really just advertisements for the live show, but that's my opinion; companies should, I agree, be free to disagree. But I'm not convinced it will be possible for long: we have to deal with the reality of the tools we have available. It's not that lock-picks make stealing ok, it's that we're talking about something to which those analogies do not apply. We have to start over.
This begs the question of mob ownership. The rights of a person are granted in opposition to the rights of other persons and of the People as a whole: just because everyone's stealing, it needn't be considered right. But certain things -- particularly, everything considered 'intellectual' property -- after certain times become cultural possessions. But does that make the recipe of Coke public domain? Few are likely to argue that it does. But you can make a reasonable argument that people should be able to redistribute Star Wars in its original form if George Lucas intends never to again. There's plenty to debate, and it should be debated.
Finally, competitive pressure is always good. The scale of the competing bodies now is so grand that we win most of the disadvantages native to monopolies. New approaches to intellectual authority would encourage smaller businesses, which would in turn would push competitive practice, and each would be free to offer freedoms that their competitors didn't (and to find, quite naturally, whether they can survive).
The point isn't that people shouldn't get to control their work; it's that we must not pretend it's property. There are a lot of vagaries and open questions if you leave that fiction behind -- daunting questions. But they need to be asked and they need to be answered. Some of them can be answered constitutionally, some of them reasonably, some of them only by practice: but they absolutely must be answered.