Back in 1994 at the Denver Zoo, a polar bear named Ulu gave birth to twins and promptly rejected them. The cubs were rescued by a zookeeper, put in incubators, and fed with eyedroppers. 
Named Klondike and Snow, they were the first polar bears successfully hand-raised by humans. People around here went nuts over the adorable little critters, which were a marketer's dream. They gained national attention (including a PBS special), were celebrated in a video and a book, and made the zoo a boat-load of money. When the bears approached adulthood, due to space constraints (and perhaps loss of cuddliness), they were sent to Sea World, a move that caused great consternation locally, complete with petitions and protests.
I remember all the hype, adoration, and frenzy over Klondike and Snow. I don't remember anyone calling for them to be put to death. Not even animal-rights activists.
Times have changed. Animal-rights activists today would rather see a polar bear die than be raised by humans. In Germany, some say Berlin zookeepers are violating animal-welfare laws by not killing little Knut:
Everyone loves Knut. The three-month-old polar bear born in one of Berlin's zoos has become a star in the German capital and has won hearts the world over. Indeed, the exact date of his first public appearance — likely to be made later this week — is the subject of almost as much anticipation as the details of Britney Spears Alcoholics Anonymous love affair. It's impossible not to love the little guy, right?
Well, not quite. Animal rights activists, as SPIEGEL reported Monday, aren't so enthralled with the polar bear baby. They are concerned that Knut, who is being raised by human hand after his mother rejected him, is in danger of losing touch with the bear necessities. Some would like to see him dead.
"Raising him by hand is not appropriate to the species but rather a blatant violation of animal welfare laws," animal rights activist Frank Albrecht told the mass circulation newspaper Bild, whose front page headline Monday read "Will Sweet Knut Be Killed by Injection?"
Berlin Zoo is allowing Knut to be raised in such a way that the bear will have a behavioral disorder for the rest of his life, Albrecht believes. "In actual fact, the zoo needs to kill the bear cub," he adds.
He's not alone. Wolfram Graf-Rudolf, director of the Aachen Zoo, told the newspaper, "I don't consider it appropriate for the species that the little polar bear is being raised on a bottle." The animal will be fixated on his keeper and not be a "real" polar bear, he says. However he feels it is now too late to put Knut out of his supposed misery. "The mistake has been made. One should have had the courage to put him to sleep much earlier."
Kill Knut because he's not a "real" polar bear? This is the PETA view of animals. Such people argue that animals have "rights" that forbid us from eating them, wearing them, riding them, putting them in zoos or circuses, having them as pets, or benefitting from them in any way whatsoever. Then they turn around and declare an animal worthless and unfit to live because dependence on humans has ruined its animal "purity" and "humanized" it. It's not love of animals that drives such people, it's hatred of humans.