At the Daily Beast, Jake Adelstein writes about shifting cultural norms around the consuming of whales as food:
In the United States, serving whale meat can cost you decades of jail-time as one sushi chef in Los Angeles recently learned; in Japan it costs you about $10, for the whale tempura special (￥980). If you go to one of Tokyo’s most famous whale specialty restaurants, Ganso Kujiraya (The Original Whale Seller), on a weekday, you can sometimes have the raw whale sashimi set for the same price; it comes with fresh ginger, soy sauce, salad, a steaming bowl of rice, and soup. While you’re there, you can pick up some whale bacon too as a souvenir. And if you’re a kid enrolled in the Japanese public schools, your chances of getting to eat it in 2013 are twice as good as they were last year.
Apart from the many ethical and conservation arguments to be made for not killing and eating whales, there's this: their meat is very high in mercury.
As noted in his piece, Boing Boing has recently covered the story of a Japanese sushi chef in LA who's looking at a possible maximum sentence that amounts to life in prison for serving sushi from the endangered Sei whale.