The recent execution of twelve men, for crimes such as rape and violent behavior, caused anger both in Iran and outside. This, according to a post in the Iranian Digg, is the scene of that execution as shown in the national television. I am not able to verify the authenticity of the image, but I will not be surprised if this is in fact a real picture.
Update: The picture is most likely to be authentic. Because it is viewed for more than 1500 times, in the source, and has received 142 comments. There are arguments there as of the relevance of crime and punishment, but to my knowledge no one has argued against the authenticity of the image. As of the poor quality of the picture, it is taken off a TV screen.
Update II: Interview with the men right before the execution, broadcast on the national television (File removed for bandwidth constraints)