Who's talking open source? I never mentioned it.
The fact is that, even without looking at other source and "copying it", programmers come up with the same answers time and time again. These got given the trendy name of "Patterns" a while back and various people coined it in providing consultancy, frameworks, libraries, tutorials etc and nary a patent in sight. This is how it should be.
Can you imagine the Internet or the World Wide Web if ARPA, Sir Berners-Lee etc had patented all their ideas, rather than throwing them out there to be improved upon? You can't, and that's because it probably wouldn't exist.
"You linked two networks? PAY YOUR LICENSE FEE!"
"You used a hyperlink? That will be $0.01 per link as a fee, please. PAY UP OR BE SUED!"
There are dating sights graphical suites and a whole host of other software that is patented when they are nothing more than a jumped-up mathematical operations (usually a matrix transform of some kind). This is a patent on pure maths - can you see how monumentally DUMB that is?
Then we have patents infecting other things such as standards. If OO/LO wish to compete with MS, they need to support the "Office Open XML" standard; which they cannot do without breaching MS's patents. This means no one bar MS can fully implement an ISO standard without breaching patents or MSs covenant [not] to sue. Can you see how STUPID that is?
Patents are the wrong tool for protecting software. Just as a hammer is the wrong tool for stirring tea.