Comment Re:Which meaning of "free"? (Score 1) 112
It is a patentable subject, but overcoming prior art is usually quite difficult.
Maybe in a country with a sane patent system, but in the US, an estimated 30% of granted patents are duplicates.
Source: http://www.thisamericanlife.org/radio-archives/episode/441/when-patents-attack
While I thought the program was extremely interesting and a good listen, if that sort of thing isn't for you, you can read the transcript. http://www.thisamericanlife.org/sites/default/files/TAL441_transcript.pdf -- the statistic is near the top of page 10.