Microsoft and Tangibility of Software
One argument against intellectual property is that property rights should be recognized only in scarce (rivalrous) resources. Some refer to this quality as "tangibility," somewhat inaccurately in my mind, but it's at least a similar concept. Anyway, the basic idea is that, say, "software" is not property because it is not tangible or scarce; therefore, copyright in software is illegitimate.
Of course advocates of copyright in software have to maintain that lack of tangibility is no barrier to software's being protected by property rights. Like, say, a Microsoft. So it's somewhat ironic to see Microsoft arguing that the intangibility of its software makes it different from normal, physical property for purposes of a US patent law provision that makes an exporter of technology liable for patent infringement if the thing exported is combined outside the US with a computer to result in a device covered by a US patent. In other words, Microsoft wants to have it both ways: software ought to be covered by copyright, even though software is not tangible. Yet, because it's not tangible, it should not be counted like a tangible component would for purposes of the patent-export law.