"It becomes a witch-hunt when he encourages people to submit prior art to invalidate the patent, thereby wasting everyone's time and money."
If there is prior art that invalidates the patent (and on a cursory examination taking a few minutes, I have found prior art dating back to 2008 that covers the main claim), then it should be submitted and the patent invalidated.
That isn't a witch-hunt, that is the system working, albeit belatedly.
As I stated in another comment, there may be legitimate prior art, but the author did not claim that. He based his claim on art that existed after the filing, and was wrong to do so.
> It becomes a witch-hunt when he encourages people to submit prior art to invalidate the patent
It's curious that you did not justify this statement. The author did not (to my reading) encourage people to spam the USPTO with the same prior art submission that he/she did. I might agree with you that such a move would be counter-productive. The reality, though is that submitting prior art to a patent application is how the system works, so how can encouraging people to work with the system be considered a witch-hunt?
Sure, the author is encouraging people to do so as a way to 'spite' Makerbot, but the end result is that the USPTO has crowd-sourced prior art with which to make an informed decision (and this is not a bad thing).
If there is prior art that invalidates the patent (and on a cursory examination taking a few minutes, I have found prior art dating back to 2008 that covers the main claim), then it should be submitted and the patent invalidated.
That isn't a witch-hunt, that is the system working, albeit belatedly.