A still from the documentary Blackfish. (Dogwoof Global)

The practice of using animals for entertainment has long been controversial. In 1903, Thomas Edison was allowed to film the execution of Topsy, a circus elephant who had killed three men. He suggested hanging the animal, thinking it would be more visually striking, but the ASPCA protested, so electrocution was used instead. Thousands of people across the country saw his film of the electrocution.

But widespread discussion of the topic has been relatively quiet ever since the American Humane Association began monitoring the treatment of animals on film and television sets in 1940. (Though activists note the group's methodology has gaps: It doesn't cover the off-set training sessions, where cruelty can take place.)

Lately, though, the issue has been making headlines with surprising frequency. Last year, HBO's Luck was canceled amid protests over the deaths of two horses on set. Similarly, Peter Jackson was criticized for the deaths of up to 27 animals being used in The Hobbit. Now it appears we may be reaching a watershed moment, and on this particular issue, our society is working just how it is supposed to: with government and private industry responding meaningfully to changing social values.

Let's start with government. In June, the United States Fish and Wildlife Services responded to a petition by the Humane Society of the United States and other animal protection groups by issuing a draft rule that would classify all chimpanzees as endangered; currently, there is a split listing that allows captive chimpanzees to be considered only threatened, allowing them to be used in entertainment, while wild chimpanzees are given the protection that comes with the status of "endangered." If the new rule were enacted without any changes, it would make it extremely difficult to use chimpanzees in television, the movies, or in circuses (as well as in experimentation).

Even if the federal government backs down, the market—or at least Hollywood—is already responding. This summer's hottest documentary is Blackfish, which, in showing both the intelligence of sea mammals and the degree to which they suffer in confinement, makes a compelling case for ending their captivity at water parks like Sea World. Later this year, Woody Harrelson, a vegan, voices the lead character in Free Bird, an animated film that chronicles the effort of a pair of turkeys who travel back in time to get their ancestors off the plate at the first Thanksgiving, thus saving the lives of millions of unborn turkeys. In 2011, Rise of the Planet of the Apes eschewed both live chimpanzees and men in bad ape makeup, instead using cutting-edge motion-capture technology to create incredibly lifelike chimpanzees onscreen. The ethics of this choice were reflected in the film's plot, a feature-length animal liberation fantasy—which is especially telling when compared with the 1968 original, in which the apes were decidedly the villains.

Just last week, Pixar announced that it was rewriting the ending of its upcoming film Finding Dory (a sequel to Finding Nemo) after John Lasseter and Andrew Stanton of Pixar met with Gabriela Cowperthwaite, director of Blackfish. According to a Los Angeles Times source, the studio decided to rewrite the ending so that the marine mammal characters no longer end up at a SeaWorld-type park. Lasster and Stanton reportedly told Cowperthwaite that they didn't want to look back at Dory in 50 years and have it be their "Song of the South." For those unfamiliar, South was the 1946 animated film criticized by the NAACP and others for its stereotypical depiction of African-Americans. It has long been considered a stain on the Disney brand, and it's clear that Lasseter and Stanton see animal rights as an issue that could one day be considered as mainstream as civil rights.

All of these developments are just a small part of a widespread animal protection movement that seems to grow stronger every day. With the rise of the Internet, news and video of animal suffering has reached hundreds of millions of people in their homes, and animal protection organizations like The Humane Society of the United States and PETA have seen surges in membership. Two percent of the population now consider themselves vegan, an area in which Hollywood, once again, seems to be leading the way. The list of vegan celebrities is long and impressive (Ellen DeGeneres, Alec Baldwin, James Cameron, Michelle Pfeiffer), and we even have our first vegan ex-president in Bill Clinton.

But Hollywood is, above all else, a profit-driven entity, and we can't expect it to change practices on ethics alone. That's why this movement will likely grow only as fast as the technology allows. But it's starting to allow quite a bit: Earlier this year, Adrien Brody recorded the voice-over for a powerful PETA ad that showcases a CGI chimpanzee more lifelike than anything seen on film before. Just as lab-grown meat has the potential to make the killing of animals unnecessary for food, motion-capture technology and CGI can one day make the use of exotic animals in entertainment a thing of the past. If that comes to pass, we may be living in a key moment in a social struggle whose historical significance many are just now beginning to grasp.