The idea of the insider who, despite pressure from authorities, employers, families and friends, decides to do the right thing and blow the whole operation sky high, has been the source of some pretty terrific drama for getting on half a century now. The latest addition to the canon is "The Whistleblower," which sees Rachel Weisz as a U.N. operative who risks everything to expose a sex trafficking scandal among her colleagues.

While it involves yet another great performance from the actress, the film ain't so hot (read our review here), but there are plenty of better options in this endlessly fascinating sub-genre, from Marlon Brando in "On The Waterfront" to Matt Damon in "The Informant!" So what makes these stories of insider dealing and clandestine informing so compelling? Is it the subterfuge, the drama, the tangled web our heroes weave when they, essentially, turn spy against the institution that has until then courted and counted on their loyalty? Is it the inspiration to be gleaned from the moral that one right-thinking person really can make a difference, despite insuperable odds, if they have the strength of character? Or is it, simply, that as scandals break around us every day, and as our faith in old institutions (the banks, the church, the government, the media) is ever more eroded we look to the movies to provide cinematic justice and accountability where too often none exists in real life. These are stories in which individuals make tough choices, listen to their consciences and pick sides, often risking life, limb and the good opinion of the people they love -- whether a whistleblower is a hero or a rat depends, after all, on your point of view. We may believe less than ever in the benevolence of corporations, organizations and the power-wielding elite, but as long as there are Davids who take on these Goliaths, whatever the cost and whatever the outcome, there is still hope.

With "The Whistleblower" hitting theaters on Friday (and the topic in the news again, thanks to the endlessly gripping scandal developing at News International), we've delved into the history of the genre to pick out some other notable examples. Check them out below.

"All the President's Men" (1976)
One of the greatest newspaper movies of all time is also one of the best whistleblower movies of all time and easily one of the best movies of its decade; "All the President's Men" is an enduring, paranoid classic. Based on the bestselling nonfiction book by reporters Carl Bernstein and Bob Woodward (played in the film by Dustin Hoffman and Robert Redford), Alan J. Pakula's film is a straightforward drama about the unraveling of a presidency that plays like a crackerjack thriller. Like all the best films based on historical fact, that we know the story (including the ending) doesn't take away at all from the experience, which thanks to William Goldman's no-bullshit screenplay and Pakula's stylish but never showy direction (that amazing Library of Congress shot!), effortlessly gives off an edge-of-your-seat sensation. The true whistleblower, of course, was Deep Throat (played by Hal Holbrook), who provided our intrepid reporters with the missing puzzle pieces to blow the whole thing wide open. As a historical figure and a literary character he has proven endlessly fascinating, inspiring a scene in "The Simpsons" and a character on "The X-Files" among other things (the real Deep Throat was only outed a few years ago). "All the President's Men" would go on to be hugely influential on one of the most peerless masterpieces in more recent memory – David Fincher's "Zodiac" (which shares 'Men's' composer, newsroom setting, and even a couple of jokes). But unlike "Zodiac," "All the President's Men" has a true ending. And oh, what an ending it is. [A]

"The China Syndrome" (1979)
Released mere weeks before the real-life nuclear accident at Three Mile Island, "The China Syndrome"'s reception undoubtedly benefited from its topicality and seeming prescience. But the film still holds up years later as an effective, compelling thriller. Admirably stripped of unnecessary embellishments like a romantic subplot or an overly tricksy shooting style, instead it focuses on Jane Fonda's TV reporter, ambitious to graduate from fluff pieces to hard news, after she and her cameraman (Michael Douglas) witness a nuclear near-disaster, which is only narrowly averted by company employee Jack Godell (Jack Lemmon). Godell's subsequent transition from line-toeing company man to suspicious investigator to justifiably paranoid whistleblower, provides the film with much of its emotional power, detailing the toll that such activity can take on one good man, who is inevitably treated as a pariah by colleagues anxious not to rock their bosses' boat. One of the highlights of James Bridges' directorial back catalogue, it is said that his more classical style of filmmaking found him out of favour in the blockbuster era of the 1980s. But this restraint means the film has stood the test of time well: in its low-key tone it is almost the archetype for a whistleblower film, yet it never feels too familiar. It garnered Oscar nominations for Fonda and Lemmon, and also for the script, though ironically, Fonda was beaten out by Sally Field for "Norma Rae," another whistleblower movie that unfortunately we haven't had time to include here, in a role Fonda herself had turned down. [B+]

"The Constant Gardener" (2005)
Fernando Meireilles’s follow-up to “City of God” begins with shots of the Kenyan landscape that are beautiful--hauntingly so, especially when you realize that you’re looking at the aftermath of a murder. “The Constant Gardener” doesn’t waste a second in revealing the death of activist Tessa Quayle (Rachel Weisz in an Oscar-winning performance), the wife of unimportant British diplomat Justin Quayle (Ralph Fiennes), but it does take its time getting to the reasons behind her killing. Though it’s based on a novel from John Le Carré, “The Constant Gardener” is more like poetry, lacking a linear narrative and boasting perfectly composed shots alternately from a shaky handheld camera and a smooth steadicam. The juxtaposition continues with its themes and moods; it’s at once utterly romantic and strikingly realistic, both in its depiction of the marriage of Tessa and Justin and the portrayal of the heartbreaking poverty and corruption in Kenya. Tessa is moved by what she sees, as well as troubled when things don’t add up, and her investigation into the issues she has discovered is mirrored by her husband’s own search for answers following her death. Weisz is captivating as Tessa, but she’s ably supported by an unusually sympathetic Fiennes, as well as fellow greats Danny Huston, Bill Nighy and Pete Postlethwaite. [A-]