Sometimes because of edited pictures the won't accept it as a proof:
http://cdn.meme.am/instances/400x/55874093.jpg
Here i found it.
Note:
Make sure that your proof have good resolution and on this screenshot/video we can see the nickname of violator.
Screenshot shouldn't have editing, inscriptions, cutting.
It's better to load them using a picture hosting for better quality:http://imgur.com/ | http://prntscr.com/ | http://postimage.org/