[ScottBurson]

But that's exactly the difference between copyright and patent: copyright covers the expression of an idea, but patent covers the idea itself. J.K. Rowling can't sue me if I write a book that's just like Harry Potter except that the places, characters, and storyline are all different, and all that remains is that it's a book about kids growing up learning about magic at a weird school. On the other hand, if it were possible to patent such an idea, and Rowling had done so, then it wouldn't matter that I had changed all those things: the idea would still be there.

So for copyright, the absence of substantial similarity is a straightforward defense, but it couldn't work that way for patents.

I agree about the podcasting patent. There are a few cases where so many people have independently invented the thing that its obviousness is overwhelmingly clear. I don't know how often that happens, though.

[TheMagicHorsey]

It happens all the time. In fact, that's where all the valuable patent litigations happen.

[ScottBurson]

Well, from your perspective it may happen frequently, because those are the cases you get called in on. That doesn't necessarily mean that these cases represent a large fraction of the obvious patents that have been issued and that we would like to see invalidated. There are an awful lot of those, as you yourself have pointed out.

Thank you for your comments, though. It has been interesting hearing about your experiences, and I think we agree on many points.