MakerBot patents material mixing extruder (Update: maybe appropriates prior public technology!)

MakerBot applied for material mixing extruder patent. The patent description is vague and it doesn't describe much details, only that two filaments type mix in some sort of filament mixer. This could provide color mixing or material properties change (ie. for support material).

This patent application could be some sort of "defensive" patenting, it doesn't mean that the prototype even exists and it doesn't need to be approved by patent authorities.

If this is real application we might see this technology in future Makerbots.

Makerbot extruder patent with extensive description:

http://www.google.com/patents/US20140034214

Ceterum censeo: the copyright and patent system is completely broken and must be reformed or, even better, fully removed.

Update (see comments also):

Jan Schmidt filed "prior art" complaint with the patent examiner since this patent has many similarities with extruder documented on RepRapWiki almost a year previous to this application:

http://reprap.org/mediawiki/index.php?title=Mixer_extruder

http://reprap.org/wiki/File:RepRapColourMixingReport-jmc.pdf

RepRap Mixer extruder, the similarities with MekrBot patent applications are obvious 

So, could this be an attempt of major corporation to appropriate and patent publicly available technology?

MakerBot had some issues with copyright ownership on Thingiverse. Looks like they have same behavior when it comes to public / open source technology.