Cannibalism on the Eastern Front during WW2?

Finnish soldiers showing the skin of a cannibalized Russian soldier. Russia actually had to implement anti cannibalism brigades during WWII. 1940. 

Source:psychanddeath Tumblr Page

Geez.  I never knew that happened on the Eastern Front.  I've heard or rather read about some musings that downed crews in the Pacific might have been "taken" by natives and died horribly but never have I heard of this on the Eastern Front!

Of course I'm being silly and historians were purposefully leaving out "non-heroic" details.  Both the Germans and Russians were reduced to eating horses, dogs and even rats.  The step to human flesh wouldn't be that big.