No matter what your stance is on file sharing, the commercial downsides to pirating movies and television shows are obvious. Writers and directors see their work inherently devalued, and the companies financing the projects see less return — potentially impacting their desire to fund future projects. Objectively speaking, piracy is bad.

Except when it changes the world.

That ‘s the lesson at the heart of Chuck Norris vs. Communism, one of the documentaries screening at this year’s Sundance Film Festival. In the 1980s, Romania was locked down under the Communist regiment of Nicolae Ceausescu. News and media were strictly controlled, the country’s secret police used violence and intimidation to tamp down all dissent, and any entertainment from other countries was chopped up and censored before being made available to Romanian citizens, if at all.

The advent of VHS tapes and VCRs changed the dynamic, however, as a string of Hollywood films began making their way into the country via a black-market ring led by a mysterious figured named Teodor Zamfir. Underground viewing parties popped up as people gathered in secret to watch the best (and worst) work of Sylvester Stallone, Jean-Claude Van Damme, Marlon Brando — and yes, Chuck Norris. Through a series of interviews and dramatic re-enactments, the documentary chronicles how the exposure to movies let people see outside the boundaries of what Ceausescu’s government presented, planting seeds of unrest that eventually played a part in the revolution that overthrew the regime in 1989.

It’s a funny, tense, nostalgia-fueled trip full of clips from movies like Missing in Action, 9 1/2 Weeks, and Bloodsport, and speaks to the profound power movies have to change the way people experience the world. Director Ilinca Calugareanu uses her re-enacted sequences to riff on the styles of the bootlegged movies — a Romanian censorship board scene is pure Adrian Lyne, while other sequences call to mind some of the grungy, low-budget action flicks of the era. That framework keeps the documentary moving, but its soul comes from interviews with those that attended the underground screenings, and had their lives changed as a result.

"We started to want to become heroes," says one man who grew up watching bootlegs of action films and the Rocky movies. An older woman describes the eye-opening experience of watching her very first movie — Bernardo Bertolucci’s sexually explicit Last Tango in Paris. It didn’t matter if the movies were Western propaganda, says another young man; at least they weren’t Ceausescu’s propaganda.

Central to the film is the presence of Irina Nistor, the woman who dubbed the English-language movies into Romanian. Handling both male and female roles, Nistor became a folk hero to the underground cinema scene, with audiences equating her voice with the hope and freedom that the uncensored movies themselves evoked. Nistor estimates that she dubbed 3,000 movies before calling it quits, but both in the film and during a post-screening discussion, she insisted that she was never trying to ferment revolution or change; despite the danger, she dubbed the films simply because watching uncensored movies was just too exciting a proposition to pass up.

The film drags slightly in its last third, and it doesn’t connect the dots to the Romanian Revolution as clearly as it thinks it does, but neither problem gets in the way of the movie’s fascinating story. And while VCRs have long given way to pirated DVDs and now digital files, the larger theme of Chuck Norris vs. Communism is echoed every time a group uses social media to self-organize, or censored information leaks out online: technology as the mechanism by which the human spirit can rise up against oppression.

So if you like movies, you should see this one. Just don’t pirate it when you do.