What's really interesting is that Orcas will not harm humans. Orcas are actually a type of dolphin and they are highly intelligent, and social creatures.
They will eat fish, seals, Sea Lions, and Great Whites, but they don't hunt humans even though they could tear us to shreds in a second if they wanted to.
We humans however, will kill whales with abandon. Although we humans typically don't hunt Orcas like we do whales, we will capture them and put them into fucking marine parks where they live in a small aquariums akin to toilets for them and generally they die after 10 or 20 years of captivity (as opposed to the wild where they can live to be 70 or more years old). There have been cases of Marine Park Orcas attacking and even killing their trainers, but I figure the trainer probably deserved it.
Beautiful intelligent creatures.
(Edit)
Apparently I was wrong. Humans used to hunt Orcas regularly.
http://en.wikipedia.org/wiki/Killer_Whale
Ironically, the Marine Park system has served to educate the public about these intelligent creatures and change attitudes towards them.