It depends. The Whaling Japan is doing isn't good, since many of the Whales are endangered.
However, what the Sea Shepherd does is counter-productive. In actual fact, the whaling industry in Japan is dying. It's been dying for a long while. Virtually no one buys Whale-Meat anymore. The Japanese people very rarely eat it. The "research" that the Japanese claim as the reason for hunting the Whales is of little value.
But the Japanese are a proud people. I know it's a stereotype, but I've lived among Asian people my whole life, in conjunction to being half-asian myself. They value face. They value their pride. One of the reasons they continue whaling, is precisely because they see a bunch of white people calling them savages for doing it. No matter what, they do not want to be seen "caving in" to the Sea Shepherd folks. A lot of Japanese people honestly feel as if they are being insulted by the Sea Shepherd, and I don't know if you know Japanese people, but if you tell them they can't do something and that they are "savages", odds are that they will turn around and do MORE OF IT. JUST. TO. SPITE. YOU.
It's not a uniquely Japanese thing either. The US still uses cluster bombs, and many Americans actually proudly boasted of that fact after the UN tried to get them to stop using it. Many Americans said "OH YEAH! YOU THINK YOU CAN TELL US WHAT TO DO! WELL, WE'RE GONNA MAKE EVEN MORE! SO THERE! IN.YOUR.FACE!!!!.
The Japanese aren't even really all that keen on Whaling. As I've said, the industry is dying. Without Government support, the industry would completely die. They sustain the industry, precisely because we tell them not to. They feel that their honour is being insulted and that they are being told to, like children, to stop something that they've been doing for ages.
Americans and Australians: You don't like being told, DEMANDED to stop things that others consider barbaric. Many Vegetarians and some Hindus believe that the Cattle Industry in Australia is similarly "barbaric". Many Australians would not like Indians ramming the ships transporting our cattle to Indonesia while chanting "SHAME, SHAME AUSTRALIA!", now would we?
The Japanese also believe there is a racial element to this: that they are being targeted because they are Asian. Frankly, I've seen some talk from the Captain of the Sea Shepherd himself that indicates that he does not like Japanese folk very much. His language and tone while specifically addressing the Japanese is NOT helpful.
The Australian government has ACTUALLY made some good strides in reducing the amount of whaling that is being carried out. It's certainly no where near the level that it was in the early 20th century. And we got that reduction by TALKING to the Japanese and reaching an agreement as equal nations. NOT by insulting them and screaming at them.
Frankly, I really do think that many of the Sea Shepherd's antics are designed more to bolster their own ego and sense of self-righteousness. They get a little noble thrill every time they harass the Japanese. For them, results don't matter. It's the THRILL, it's the NOBLE FEELING, it's the ANTICS that matter. They are more in it for their own smug sense of self-satisfaction than to make any real, tangible progress. And their tactics are dangerous, and getting more dangerous with every passing year.
The Australian Press ignores them now. Most animal welfare charities ignore them. The Japanese government doesn't listen to them, and the Australian people have long since grown tired of them. I know I have. I donate to the WWF. They are a good organization that often GET RESULTS, THROUGH HARD WORK. Not an organization dedicated to GRAND STANDING for the sake of ATTENTION and EGO, which is what the Sea Shepherd is.