I remember working at one temp job where I made some friends. One in particular (Trixie... I will not explain the origin of her name) was a hardcore IP proponent. Just to be contrary, I took the other side. But the more I think about it, the more I think it was the right side to be on.
However, this is an area I know only a little about. What I know about it is that the RIAA used it to shut down Napster and Grokster and take a bunch of people to court for copying music that is far too expensive in the first place.
I also know, or at least have read, that it is used to protect people's inventions. Though, these days it seems that pharmaceutical companies use it to prevent others from taking away their market share. There is the argument that the company, like a lawyer working on contingency, takes great risks ot produce the medicines and as a result they should reap the benefit of that.
But as I was reading over at Greedy Trial Lawyer, this argument may not be as strong as I once thought. The full article against patents and pharmaceutical patents is found here.