In late 2007, filmmakers Ariel Schulman and Henry Joost sensed a story unfolding as they began to film the life of Ariel's brother, Nev. They had no idea that their project would lead to the most exhilarating and unsettling months of their lives.

Controversial doco poses more questions than answers.

The word on the web is that Catfish, a documentary that aims to trace the tortuous saga of a long-distance internet 'love’ affair, which turns out to be a story full of mystery, longing and betrayal, may well be too good to be true. After it premiered in Sundance in January 2010, there were already a lot suspicious whispers. Maybe that’s because Catfish has the propulsive mood of an airport novel, and characters that wouldn’t be out of place in modern gothic fiction. Some of the 'cast’ of real people here seem to live in a world of delusion and they hide their lives of hardship behind glamour and sex (or the promise of it). It’s got 'plot’ reversals, suspense, and more than one scene of emotional catharsis. Documentaries, even the elegant, stylised worlds of, say, Errol Morris, tend to reflect the contradictory messiness of life. When the factual filmmaker can’t find drama to film or action to edit into pathos, they offer up something to think about.

Not Catfish. It boots up quick and chases after its plot so relentlessly that there’s little chance to start wondering about what might be, could be or probably is. It’s so compelling moment to moment, it begs to be left alone, and merely consumed. It has the hypnotic 'what’s going to happen next?’ quality of a soap opera. Still, no one should be misled about the kind of movie experience that’s on offer here.

Shot up close, often in cars, streets and anonymous rooms on a variety of digital formats, that give the image that pixelated, gauzy quality familiar to Skypers everywhere, a lot of its screen time is dedicated to scenes featuring Nev Schulman, the movies 'leading man,’ holding a phone to his ear. When he’s not doing that, he’s reading mobile texts on camera. In terms of visual excitement, that’s about as gripping as, well, watching someone talk on the phone. We spend a lot of time with Schulman but we don’t really get to know him. We find out nothing of his romantic history, and there’s no hint of an inner life. Early in the movie he complains to camera that he’s 'not very interesting." By movie’s end, there’s no evidence to disagree with him.

Aside from Schulman, who happens to be a New York based photographer (a fact that becomes important to 'the plot’), the other big on-screen character in Catfish, for a large part of the movie’s running time, is Facebook. The social network keeps shifting its shape as Schulman falls deeper for a seemingly wholesome provincial girl called Megan, who he has never met in person. Realistically, Facebook is a mere means to an end; it’s a communication device. But Catfish turns Facebook into an object of mythic proportions. The filmmakers, who turn out to be Nev’s brother Ariel and his buddy Henry Joost, seem to observe Facebook etiquette with something close to reverence; when they discover, in the course of the film, that a close Facebook friend is 'lying,’ they seem close to tears. Invested in the alleged intimacy that Facebook is supposed to provide, they are distraught at the thought that someone has had the temerity to 'break’ the social contract. But all this seems a little convenient and a little glib.

Viewed with clear eyes, Facebook simply provides the means for a virtual relationship, and this is its magic – it allows us all the chance to project an image, an upbeat fantasy of ourselves, which can be in a way that’s never quite wholesome or rather healthy. But it can also be a venue where the user can forget about the real world and conjure an alternate universe (which is why so many seem to be sceptical about Facebook as a matter of course). This is heady stuff; the social, cultural, ethical and moral implications of social networking is hardly a subject that’s been exhausted.

If Catfish has value, it’s in the fact that its very premise allows the queasy questions of authenticity and identity to rise up. But the trouble is the filmmakers seem to be stylists and opportunists; Catfish has the slick gloss of hipster media magazine journalism. Its deeper questions are never probed. Essentially, Catfish is basically a 'gotcha yarn’ about a crew of New York 'media players’ chasing down a Facebook fibber"¦ or not. If this review seems lacking in specifics that’s because Catfish is virtually impossible to write about since much of its incidental pleasures lie in the fact that its kick derives from its capacity to give an audience a head-spin from its 'shocking discoveries’ (and close encounters of the personal kind).

Still, it’s easy to see why Sundance punters (and others) were more than a little dubious about this rather sanctimonious film. It asks us to believe that Gen Y New York media professionals are naïve and ingenuous when it comes to Facebook and its capacity to define 'identity’; whenever they find an inconsistency or inconvenient 'fact’ about Megan, they are gobsmacked about her lack of sincerity. Of course, if they didn’t there wouldn’t be a movie. To be sure, Schulman seems to have his heart set on Megan. Is that lust talking? How real can these feelings be when there is nothing like genuine intimacy? But nobody ever stops to ask the obvious question: Given what Facebook is, why wouldn’t you want to lie about yourself, just for the fun of it?