I don't know whether this is a mistranslation in the title thread, but if this wikimedian is "advertising to make images "for the wikimedia foundation" and then suing users" that would seem to me a different thing to taking images for himself but releasing a CC-BY-SA version on Wikimedia Commons. That wouldn't make any difference if he was taking photos of mountains or wildlife, but if he is using the foundation's name to get access to celebrities then that would be different. Taking photos for himself but releasing a copy on Wikimedia Commons under CC-BY-SA is slightly different and someone who speaks his language might need to suggest that to him.
I would also be interested to know whether he is suing people who are taking the same interpretation of the CC licenses that Wikipedia uses, or only those who are not following the reuse guidelines in Wikipedia or Wikimedia Commons.
It isn't clear to me at present whether he is:
1 insisting on his undisputed licence rights 2 strictly enforcing licence rights which we acknowledge on at least one Wikimedia project and don't ourselves breach as a movement 3 enforcing licence rights which we acknowledge on at least one Wikimedia project but breach on another.
I and perhaps others whose German skills are like mine barely adequate to order a beer, would be grateful if a German speaker on this list could clarify this.
Regards
WereSpielChequers