This article causes me to question my trust in BoingBoing and Cory Doctorow. The extruder is not the only open source component Makerbot is trying to patent, here's another one http://www.openbeamusa.com/blog/2014/5/22/stay-classy-makerb... Seems the open spirit of Makerbot has been run aground by their new corporate owner.
I still find it very strange that comments were so hard to make on that story. It seems almost like Boing Boing wasn't interested in a normal discussion.