Officials in Tokyo condemn these actions, claiming that four members of the Nisshin Maru's crew were injured. Sea Shepherd's Paul Watson, who is currently aboard the vessel, denies these allegations.
The Japanese plan to kill upwards of 900 minke whales + 50 fin whales during the expedition. According to their government, they pursue whaling for scientific research purposes. Critics are skeptical of their motivations, and claim that data can be collected without killing the whales.
Here is some footage from the activist's viewpoint: