SeaWorld announced changes this week to the treatment of orcas at their theme parks, a move influenced by the 2013 documentary Blackfish which explored the risks and ethical implications of keeping killer whales in captivity.
The decision is testimony to how powerful documentaries can effect change - and with that in mind we've rounded up 27 of the most groundbreaking films released in the last few years.
Block book three days off work to get through all of them. We dare you.
This gripping documentary breaks down the events that have led to three separate deaths at SeaWorld California caused by a male whale Tilikum, who was captured off the coast of Iceland in 1983.
Six weeks before winning Miss World in 1998 aged 18, Israeli Linor Abargil was raped. Abargil spoke out, taking her rapist to court before becoming a campaigner against sexual violence. Brave Miss World tells her story.
Georg Cantor, Ludwig Boltzmann, Kurt Gödel and Alan Turing were all brilliant mathematicians - and they all took their own lives. This BBC documentary explores whether their genius led to their deaths.
This heartbreaking 2015 film tells the story of a Syrian family ripped apart by the Assad regime from 2009 onwards - detailing both the repression in the country before the outbreak of civil war and the outward horrors that have followed.
Programming prodigy Aaron Swartz helped create the internet as we know it today. Before taking his own life aged just 26, he was involved in the development of RSS, the Creative Commons licence and the social news site Reddit. This is a film about his extraordinary life, and his premature death.
After filmmaker Laura Poitras received encrypted emails from someone who wanted to talk about the NSA's surveillance programmes, she and reporter Glenn Greenwald flew to Hong Kong to meet the sender. He was Edward Snowden, and pretty soon the wholw world knew his name.
In 1974 Philippe Petit was arrested after an illegal, hour-long high-wire walk between the twin towers of the World Trade Centre, 1,350ft above the ground. The next week, he turned 25. This 2008 documentary is the story of the "artistic crime of the century".
The controversial documentary about the gang rape and murder of Jyoti Singh, a 23-year-old medical student on a bus in Delhi in 2012 caused outrage in India, where the authorities did their best to ban it.
In interviews with the men who killed her, now behind bars, the film is a shocking look at the status of women in India.
This jawdropping 2014 documentary captures pundits and propagandists for hire talking on camera about how they plant seeds on the risks and benefits on behalf of pharmaceuticals, oil companies and the tobacco industry.
Israeli Ari Folman knows he was a soldier in the 1982 Lebanon War - but he can't remember anything about it. Waltz With Bashir is an animated documentary about Folman's search for his lost memories and the horror he was trying to forget.
Brenda Myers-Powell is a former prostitute who now runs the Dreamcatcher Foundation, a charity helping exploited and vulnerable women in Chicago leave the sex industry. The powerful film shatters stereotypes about sex work and humanises women who are often treated as two-dimensional in other media.
Ayrton Senna is considered one of the greatest Formula One drivers of all time. He won the Formula One world championship three times before dying in a crash during the the 1994 San Marino Grand Prix, aged just 34. This 2010 film focuses on his life, rivalries and his fight to improve the safety of his sport.
The Square documents the efforts of Egypt's revolutionaries as the country teeters between military rule and the Muslim Brotherhood in spiralling chaos since the Arab Spring, centred on Cairo's Tahrir Square.
This 2005 film chronicles the life and premature death of film-maker Timothy Treadwell and his girlfriend Amie Huguenard, who were killed by a grizzly bear in Alaska in 2003. It features video footage of bears taken by Treadwell during the last years of his life.
This film follows one man's attempt to get the highest score in the world in arcade game Donkey Kong. Don't be put off if you're not a gamer: this isn't just a documentary about Donkey Kong, it's about living your dreams.
This controversial 2011 documentary focuses on model scout Ashley as she travels to the Siberian countryside to discover fresh faces and Nadya, the 13-year-old she finds there and sends to work in Japan.
In this 2015 documentary miniseries from HBO, Robert Durst, the eccentric millionaire who was accused of murdering his wife and two others, actually confessed to the crimes whilst mumbling to himself in the bathroom, apparently unaware the mic was still on.
Durst was arrested on first-degree murder charges the day before the finale aired.
Film maker Liz Canner's job editing erotic videos for a drug trial allowed her to take a behind-the-scenes look at pharmaceutical companies - and their struggle to understand the science of female pleasure. Orgasm Inc. is the result of years of work documenting the race to develop a Viagra for women.