... for uploading a copyrighted file and marking it as in the public domain. There's a visible copyright notice on the page that you downloaded File:PaperChax.PNG from.
I've corrected that for you.
Please take more care with file licenses in the future. We admins need to set the right example for the rest of the tropers, after all. :)
@Labster @GethN7 @Looney Toons @QuestionableSanity @Derivative @SelfCloak