I can't prove it, but I'm pretty sure I saw someone post photos to wikimedia under a CC license. But then later claim that person was an imposter and wasn't aut

I can't prove it, but I'm pretty sure I saw someone post photos to wikimedia under a CC license. But then later claim that person was an imposter and wasn't authorized to do so. Now they get to make claims against anyone who, in good faith, used the wikimedia image believing it to be CC.