In an answer to a recent question, the answerer referred to a diagram that I'm pretty sure was not something he/she created. I'll refrain from mentioning the specific answer to avoid any conflict, but I did wonder whether answers like this should be flagged.
I am aware of this discussion, which does conclude that images should be sourced. OTH, in the accepted answer for that thread, @Pondlife does say that "you cannot expect moderators to take care of this".
Does this mean we should just allow the voting process to police this?