Yes, public sources as in the tax payer. It is worth pointing out that Fraunhofer is itself a non-profit organization.
The argument that anything funded by tax money must be open is a very fair stance. Though the line gets very blurry when you mix various sources of funding like this. To the best of my recollection I have yet to be paid from any public funding (rather than project specific funding raised from the industry, for example).
Personally, I have no qualms with the funding model, but other points of view are presumably equally valid.
You're right, but I'm not aware of any egregious salaries or bonuses. Both the president and all the chairmen are all professors, which generally means they are paid by their University, not Fraunhofer. The same applies to many directors of the individual institutes. The salaries for employees are based on "Tarifvertrag öffentlicher Dienst" ("labor agreement for public service",). Unless there's straight up fraud somewhere, there shouldn't be too much lining of pockets.
The argument that anything funded by tax money must be open is a very fair stance. Though the line gets very blurry when you mix various sources of funding like this. To the best of my recollection I have yet to be paid from any public funding (rather than project specific funding raised from the industry, for example).
Personally, I have no qualms with the funding model, but other points of view are presumably equally valid.