When British photographer David Slater handed over his camera to a crested black macaque in 2011, he probably didn't think he'd be on the receiving end of a lawsuit from the monkey.
The macaque took two 'selfies' with Slater's camera after he spent a long time teaching them to be interested enough in his equipment to take pictures of themselves.
The images went viral and regularly appear on social media, in blog posts, and memes.
However, as fun as the photos are, they have more or less ruined Slater's life. He is now basically broke after being dragged through the courts for more than five years.
Where the story began
The legal dispute began in 2012 when Wikimedia Commons uploaded Slater's photos as royalty free images. Slater requested the website either pay for the photos or remove them. Wikimedia Commons refused. The site said Slater owned no copyright due to the monkey pressing the shutter itself.
Slater told BBC News in 2014 that he lost out on a huge amount of revenue on the photo as a result.
"I made £2,000 [for that picture] in the first year after it was taken," he said. "After it went on Wikipedia all interest in buying it went. It's hard to put a figure on it but I reckon I've lost £10,000 or more in income. It's killing my business."
To make matters worse, animal rights activists Peta also got involved in 2015, and said all proceeds from the photos should benefit the monkey. A court in San Francisco disagreed in 2016, and ruled in Slater's favour that copyright protection could not be applied to the animal.
However, this meant that there was legally no copyright licence on the photographs at all, and the pictures remain in the public domain.
This still wasn't good enough for Peta, which challenged the ruling last year, saying that the monkey -- which they named Naruto -- was the author of the works "in every practical (and definitional) sense." The group appealed to the ninth circuit court of appeals, which heard oral arguments last week.
"Had the monkey selfies been made by a human using Slater's unattended camera, that human would undisputedly be declared the author and copyright owner of the photographs," Peta said in appeal papers. "Nothing in the Copyright Act limits its application to human authors… protection under the Copyright Act does not depend on the humanity of the author, but on the originality of the work itself."
The rights of contention in this case range from the complicated to the downright bizarre. The court must decide whether Peta has a close enough relationship with Naruto to represent him in court, what the value would be to provide a community of macaques with a written notice of copyright, and whether Naruto is actually losing out by not being the formal copyright-holder.
"There's no case that suggests that the copyright infringement itself is injury," said Judge N Randy Smith. "What's your injury? There's no way to acquire or hold some money, which the copyright would give. There's no loss as to reputation. There's no even allegation that the copyright could have benefited somehow Naruto."
There's also the question over whether Peta has identified the correct monkey. Slater claims the macaque in the photograph is a female, and it a completely different age to the six-year-old Naruto Peta is representing.
"I'm bewildered at the American court system," Slater told the Guardian. "Surely it matters that the right monkey is suing me."
Too broke to go to court
Slater couldn't attend the latest court case, which started last week, because he couldn't afford the flight to America. He's also been financially drained by legal fees, is still in debt to his lawyers, and has no real income from the photo that is all over the internet.
He's told the British media he has considered giving up his career as a photographer altogether, to become a tennis coach or a dog-walker instead.
The intention of the photographs was always good, he has said. Slater has been a conservation photographer for a long time, and says that raising awareness for endangered species has always been a priority. Crested black macaques are critically endangered, and there are only a few thousand left in the wild.
"Photographing and publicising their plight was the main driver when I visited the island," Slater says on his website. "Not only did I raise money for the conservation project, through canvas sales kindly donated by Picanova and direct print sales, but I helped the group to promote a new code of ethics when visiting these macaques in Sulawesi."
On ITV's "This Morning" on Monday, Slater said he would have worked closely with Peta on this issue to come to an agreement about funding the macaques, but the group chose not to get in contact before they brought the case against him.