Well they clearly restrict the free use of ideas. An idea that I can't use is of limited interest to me. Have you ever read a software patent ? The ones I ha

Well they clearly restrict the free use of ideas. An idea that I can't use is of limited interest to me. Have you ever read a software patent ? The ones I have seen have been written in a very strange way (ie use of non-standard terminology for technical concepts) which seems aimed at obscuring the nature of the ideas being patented rather than clarifying them. If patent descriptions were really intended to convey useful technical information they would read more like journal articles rather than some strange dialect of American legalese. I'm sure that some innovation occurs through efforts to work around existing patents however I doubt that effect comes close to matching their effect of preventing ideas, even if independently discovered, from being incorporated into new technical solutions. As for the notion that people are going to read 20 year old expired patents for their ideas that seems pretty unlikely to me given the pace of technological development.