Okay, stupid comment on your part. Sure, one of them turned out fine, but what about the rest? Where I live (California), there was recently a case where a child died because the father slightly shook him. As Ghoast mentioned, there is something called "shaken baby syndrome" (I believe that's what it is called). So if that slightly shaking a child can harm him/her, I'm pretty sure swinging them around like a rag doll can as well.
If you think this is okay, you're an idiot. Sorry to say it. I hope you don't have children. You're that one person who always wants to go against the majority, just cause you're bored. Look at the video and see how many dislikes it has, versus likes. I hope that's an indication that you're part of the small group of people who think this is okay, versus the thousands of normal people who realize that this is SICK.