Omg, why did these dog abusers tie a rope around this GSD's mouth?

I started watching it since YT recommended me the video and thought it was cute at first then it zooms in on the poor dog's mouth and there is rope around it! a href="http://www.youtube.com/watch?v=mh0199nnaYY" rel="nofollow"http://www.youtube.com/watch?v=mh0199nna…/a