The problem is it isn't your mark, maybe you feel differently because before you clicked the pixel it was white/blank. Or your group decided it would be yours. There is no ownership. There is no rule requiring cooperation or organization or socializing.

I'm not saying someone shouldn't be disappointed their art was overwritten. But again this gets back to my comment about the whole thing being divisive. You've demonstrated my entire point by saying /r/TheBlackVoid as using /r/place incorrectly.