Should parents be punished for their grown children's actions?

I recently read news accounts of an incident where a 23 year-old man was accused of vehicular manslaughter after killing a woman in a drunken driving accident. Many people commenting on the article pointed out that the young man at fault is a spoiled rich kid and accused the parents of coddling him and enabling his drug and alcohol habits. More than one commenter concluded that the parents should be punished right along with the son. What do you think?