Last year, screenwriter Mark Bomback discovered the work of indie filmmaker Alejandro Adams on Amazon's Prime Video service. He devoured two films, a toxic masculinity character drama called Amity and a gangster thriller titled Babnick, and started emailing with the Palo Alto, California-based director.

“It was like truly finding a diamond on the beach,” says Bomback, who is now helping Adams get a more ambitious project made. “None of this would have happened without Amazon.”

But when Bomback, whose credits include War for the Planet of the Apes and Apple’s upcoming Chris Evans starrer Defending Jacob, recently tried to recommend Amity to a friend, he discovered it was no longer was available on Prime Video. According to Adams, Amazon removed three of his four films from its streaming platform this year.

He's not alone. Several emerging filmmakers who relied on Amazon Prime to distribute their work report that their movies have disappeared from the platform without warning. They say they were given no warning about the removal and that Amazon informed them those titles will not be accepted for resubmission, essentially killing any chance that audiences will discover them. Their predicament exemplifies the risk of becoming too reliant on a powerful platform whose benevolence can be fleeting.

"It's disheartening because the movies were getting seen," says Scout Tafoya, who had three low-budget films removed from Prime Video, including a drama, House of Little Deaths, about sex workers in Philadelphia.

These movies made their way to Amazon via the e-commerce giant’s self-distribution platform, Prime Video Direct. Launched in 2016 with such participants as Conde Nast Entertainment and Samuel Goldwyn Films, the program opened subscription offering Prime Video to moviemakers of all sizes who otherwise might not have been able to strike a rich licensing deal with the streamer. Through Prime Video Direct, a little-known filmmaker with no Hollywood ties could suddenly stream a short video alongside Oscar winners and blockbusters. Some filmmakers upload the videos themselves, others work with indie film distributors who use the program to more widely release the titles.

Amazon has touted the way its video platform supports indie creators, previously reporting that, in its first year, Prime Video Direct paid tens of millions to rights holders. In 2017, its budding Film Festivals Stars program, launched to help films screened at major festivals find distribution through Prime, committed to more than $9.5 million in cash bonuses to independent filmmakers.

Amazon is now sponsoring its own short film festival, which will pay winners bonuses and promote their films on Prime Video. “Prime Video provides creators with an opportunity to connect with audiences around the world,” an Amazon spokeswoman said in a statement. “We have been thrilled to help creators introduce their vision to our Prime members, and we get excited to see how customers respond to unique and compelling content.”

But although it has drawn comparisons to YouTube because of its self-distribution focus, Prime Video Direct was not meant to provide unencumbered access to Amazon’s 100 million-plus membership, and Amazon says it regularly assesses the entertainment selections that are available via Prime. Essentially, titles can be booted if they are seldom viewed by its members.

Per Amazon, filmmakers have access to a dashboard that details how their films are doing. “Providers have access to a variety of performance metrics that help them understand how Prime members respond to their content,” the statement continued. "We continually evaluate our offerings to ensure we are delivering the most value to our Prime members, and as a result, we occasionally remove titles from Prime Video that our customers don't find compelling."

Amazon might have good reasons for removing these projects, but creators say the company has not been transparent about the takedowns. "It didn't make sense," says trans filmmaker AJ Mattioli, whose documentary on gender identity, Words, was eliminated in January, though three of his projects remain. Adams acknowledges his films are "challenging," but he was puzzled by the notification that Amazon sent him, saying the title contains content that doesn't meet its "customer content quality expectations.”

Being cut off from Amazon Prime also has meant a loss of income for these filmmakers, though it's pennies compared with even a modest VOD release. Prime Video Direct shares between 4 cents and 10 cents for every hour a title is streamed in the U.S. For Adams, that meant hundreds of dollars each quarter. Last quarter, he received just $4.80. Tafoya says he averaged about $20 a month from Amazon.

But few of these filmmakers are in it for the money. Instead, they see Prime Video as an important platform for establishing a following. Though they can distribute on other platforms, like transactional service Vimeo, they say Prime Video offers the most cache. “Filmmakers want audiences or, if they are career-minded, they want the visibility and discoverability that a platform like Amazon offers,” says Adams, adding, “You can’t convince A-list actors and producers to run off and pay fees to see your films, whereas they absolutely will watch them on Prime.”

It is unclear how many filmmakers have had films removed from Prime. A Change.org campaign, which calls for Amazon “to immediately replace the movies they’ve taken away,” has been signed over 3,600 times, but anyone who signs up for the site can add their name to a petition. Linda Nelson, co-founder of the distributor Indie Rights, says her company handles distribution for some 700 films and only a handful, including Adams’ titles, have been affected. "I would never recommend putting all your eggs in one basket," she says. "Indie filmmakers need to take this advice to heart and explore as many opportunities as they can to make sure their films get seen."

A version of this story first appeared in the April 30 issue of The Hollywood Reporter magazine. To receive the magazine, click here to subscribe.