"Good artists copy, great artists steal" - The CEO of Sun speaking

On his blog, (assuming he is who he claims to be - not confirmed!) he writes a nice to read story about how patents fit into the modern world IT corporation's strategy. You collect patents for defensive purposes so you can counter claims of a corporation with your own expensive claims. The only problem is that this doesn't work for patent trolls, because those corporations usually don't actually sell anything themselves.

Against Intellectual Property

Being a Linux fan you might be interested in this book(free pdf download) of two economists, which explains why they think intellectual property is often the wrong choice.