Young Iranians Arrested For Dancing In 'Happy' Pharrell Video

Age: 25, Crime: Happiness
About a month ago, 6 Iranian boys and girls (in this video) danced to the famous song by Pharrell Williams called "Happy" on the rooftops of Tehran and uploaded their video on the YouTube. It was widely distributed in the social media. The police decided to track them down and arrest them and make them repent in front of the camera.

Should people be allowed to be "happy"?
Should the state stop people being happy?
What do you think?