A National Security Agency source from Alex Gibney’s “Zero Days.” (Courtesy of Magnolia Pictures/s)

It’s getting hot out there for documentaries — in every sense of that word.

As the 14th edition of AFI Docs gets underway in Washington and Silver Spring this weekend — kicking off yet another summer packed with documentaries to counterbalance the season’s usual spectacles and sequels — contretemps have erupted over a number of nonfiction films, both inside and outside the festival.

In April, the Tribeca Film Festival and its founder, Robert De Niro, gave themselves a whopper of a black eye when they programmed then pulled the anti-vaccination film “Vaxxed.” Shortly thereafter, Katie Couric and director Stephanie Soechtig were called out for misrepresenting their on-camera sources in the gun-control advocacy film “Under the Gun” — prompting a subject from their previous collaboration, “Fed Up,” to claim that he wasn’t portrayed accurately in that film.

Although the AFI Docs program this year seems aimed at stoking conversation rather than controversy, it hasn’t been completely immune: Earlier this week “The Opposition,” about a community in New Guinea fighting a hotel developer, was pulled from exhibition after the filmmakers were sued for defamation by one of the film’s subjects; the directors of “Tickled,” about the hidden world of tickle fetishists, have also been sued by two of their sources, who showed up at a recent screening in Los Angeles claiming that material they provided off the record was used inappropriately in the film. (Screenings of “Tickled” will proceed as planned on Friday and Saturday.)

Participants’ remorse is surely nothing new in documentaries, wherein directors routinely take the raw material of talking-head interviews and trim, shape and manipulate it to their own ends, whether it’s to elicit an emotional reaction, score political points or simply create an entertaining narrative. But in an age when fact-based entertainment is ascendant, and when sources can push back easily and ubiquitously on social media, the contract between filmmaker and source is more crucial — and more subject to ex post facto argument — than ever.

AFI Docs Director Michael Lumpkin doesn’t believe these cases are necessarily on the rise. “I think it could be seen as the flip side of documentaries being more popular and getting more attention,” he said in a recent phone conversation, adding that, as a programmer, his standard is whether filmmakers make clear what kind of movie they’re making and remain true to that mission.

“A documentary can be a number of different things,” Lumpkin said. “It can be advocacy. It can be journalism. It can just be storytelling, and it can also be art. And most films, most filmmakers let you know pretty early what they’re trying to do with their film.” Red flags are raised, he explained, “when things don’t seem right for that kind of film. Does this film ring true for what it has told me it is? Is this good journalism? Is this good advocacy? Is it appropriate advocacy? And they all have to be a good story. They have to engage you to be worth showing and asking somebody to pay money to watch them.”

Although the “Vaxxed” and “Under the Gun” cases are substantively different, each in its own way addresses the other contract documentary filmmakers must honor, which is between themselves and the audience. With the resurgence of true-crime stories a la “Serial,” “The Jinx,” and “Making a Murderer” — not to mention the staged pseudo-spontaneity of reality TV — viewers have become more attuned to how writers, directors and editors craft their stories to create heightened emotional experiences, rather than convey purely objective truth.

Over the past few decades, documentary-makers have taken enormous aesthetic leaps away from the static, talking-head educational films they grew up with, embracing reenactment, animation, stylized staging and other fiction-film techniques to bring energy and urgency to their narratives. In most cases, they have striven to hide the artistic liberties they take — the better to keep the audience fully immersed in the tale they’re spinning. But such coyness is beginning to feel hopelessly dated at a time when audience expectations have changed: Today, transparency has become the new standard. Perhaps it’s time to bring that same creativity to full disclosure, whether in the form of brief explanations during opening or end credits, or more artfully within the body of the film.

That idea came into clearer focus in May, at a screening of “Weiner,” when an audience member asked directors Josh Kriegman and Elyse Steinberg how they gained such extraordinary access to their subject, disgraced former congressman Anthony Weiner. When Kriegman explained that he had once worked on Weiner’s staff, an audible gasp rippled through the audience. Conversely, in “Zero Days,” Alex Gibney’s upcoming film about cyberwarfare, Gibney made a point of disclosing the identity of one of his on-screen subjects, who is actually an actress portraying a composite character — a moment reminiscent of Sarah Polley’s masterful acknowledgment of artifice in her documentary “Stories We Tell.”

During a discussion after the U.S. premiere of “Zero Days” at AFI Docs on Wednesday, Gibney — who also used an actress in his Eliot Spitzer film, “Client 9” — explained that using a performer this time was necessary, not only for the aesthetic purposes of the film, but to ensure that his confidential sources would cooperate. Although he feels strongly that revealing the actress’s identity early in the film would undermine its dramatic effectiveness, Gibney feels just as strongly that “by the end of the movie, you should know,” in order for the pact between filmmaker and audience to remain intact.

If technology has made it easier for sources to critique how they’re presented on -screen, it has also provided an opportunity for filmmakers to head them off at the pass: Penny Lane, whose documentary “Nuts!” opens next week, has created an accompanying website, in which she scrupulously fact-checks her own film, allowing viewers to see where she hewed to the factual record, tweaked chronological and visual details or simply made things up out of whole cloth. The world of fiction film is catching on: Director Gary Ross created a similarly comprehensive website for his Civil War-era drama “Free State of Jones,” and Gibney said he’d do the same for “The Looming Tower,” an upcoming Hulu series about the rise of Al-Qaeda.

Still, it bears noting that the appendix for “Nuts!” won’t appear until months after the film has been seen in theaters, plenty of time for viewers to internalize the filmmaker’s imaginary characters and outright fictions as historical truth. As welcome as copious footnotes and annotated websites are, there’s still room for more clarity and accountability within an art form whose core value lies in being believed.

Similarly, the audience needs to remember that nonfiction filmmaking is an art form — not journalism, or a Wikipedia entry, or just-the-facts testimony that would pass muster in a court of law. The balance between truth claims and artistic license — as well as ethical duties to sources and viewers — will always coexist in creative tension; it’s in how those questions are resolved that we see the difference between a good filmmaker and a great one. The audience does well to supply its own grains of salt, but it’s incumbent upon documentary-makers to make sure that we gasp out of discovery and delight — not because we feel deceived.