In the past few months, angry fans have voiced their displeasure over the casting of Scarlett Johansson in the film adaptation of the iconic manga series Ghost in the Shell, and also Matt Damon starring in Chinese-focused The Great Wall.
But fans should pause for a second before they barrack these choices with abuse, as we’ve seen in the examples below that sometimes, the fans can be too hasty when a supposedly unsuitable actor is chosen for a beloved character...
Heath Ledger as The Joker
Christopher Nolan finished the successful Batman reboot Batman Begins with a cliff-hanger signalling the arrival of The Joker, then had the task of casting the Clown Prince of Crime.
The internet rected furiously when it was announced that Heath Ledger had been cast as Batman's most famous villain for The Dark Knight.
Batfans thought that Ledger, who had previously starred in 10 Things I Hate About You, A Knight's Tale and Brokeback Mountain, didn't have the acting chops and was just a pretty boy, and wouldn't be able to bring the gravity to the role.
Fans were shocked and delighted when Ledger morphed into the terrifying, unhinged version of The Joker that won Ledger a posthumous Oscar and has fans near-unanimous in proclaiming it is the best onscreen portrayal of the character ever.
Jennifer Lawrence as Katniss Everdeen
In Suzanne Collins' Hunger Games book, teenage Katniss is described as having brown hair and olive skin, and - coming from the constantly-starved District 12 - was perpetually underfed.
So book fans and critics hit out when Jennifer Lawrence was cast in the role - Lawrence was 21-years-old when she was cast and was well-known for her blonde hair, while some also deemed her too tall and fat to play the film's undernourished heroine.
Lawrence hit back at the claims, and silenced them once more with the release of the first Hunger Games film, when, having dyed her hair black, she helped the film gross close to $700 million worldwide and earning glowing praise for her performance as Katniss.
Renee Zellweger as Bridget Jones
When Helen Fielding's award-winning story of a thirty-something British singleton was made into a film, British actresses such as Helena Bonham Carter, Rachel Weisz and Kate Winslet were passed up in favour Texan actress Renée Zellweger.
Fans were understandably outraged with Zellweger's casting, considering Fielding's character is overweight and constantly (and unsuccessfully) attempting to shift the pounds, while the Jerry Maguire and Me, Myself & Irene star was far from overweight.
But the film's director Sharon Maguire stuck to her guns, while Zellweger worked with a dialect coach, gained 20 pounds and, at the producers' request, worked at a London book publisher to perfect the character.
The revolt about the Texan was instantly forgotten when she delivered a near-perfect English accent and endearing performance as Bridget Jones which audiences fell in love with.
Daniel Craig as James Bond
Pierce Brosnan hung up his 007 tuxedo after finishing Die Another Day, and it was announced in 2005 that Layer Cake star Daniel Craig would pick up the torch as the next Bond, which sent the public into a frenzy of anger.
Most fans' issue with Craig's casting was that he'd be the first Bond with blonde hair, as well as thinking that he looked too 'rough and ready' instead of the usual suave, sophisticated Connery, Moore, and Brosnan.
Choosing a more rough-looking actor for Bond fitted in perfectly with the new gritty 'back to basics' direction that they were taking Bond for Casino Royale, and the film was praised as one of the best Bond outings for many years.
After four appearances as the agent, virtually everyone has agreed that Daniel Craig is as good a Bond as his predecessors, as are studio bosses at MGM, who are throwing millions at Craig to reprise the role after the actor declared he was finished with the Bond movies.
Ben Affleck as Batman
Batman fans seem to have short tempers and short memories when it comes to casting, as the same fans whose uproar about Heath Ledger proved unfounded, went into a frenzy when the first Batman post-Bale was announced.
Fans declared Affleck, who had earned some recent praise for performances in Argo and Gone Girl, was a terrible actor and looked nothing like the Caped Crusader.
When Batman v Superman: Dawn of Justice came out, audiences had plenty to complain about, as the film was seen as a huge disappointment, but Ben Affleck's performance as the Dark Knight was praised by many and seen as one of the few positives in the underwhelming BvS.
Robert Downey Jr. as Sherlock Holmes
The famous fictional detective was well-known for being a tall, thin, Englishman, so fans were irked when 5ft 8in American Robert Downey Jr. was announced to play Arthur Conan Doyle's creation.
True Holmes fans would know that Doyle's character had a 'Bohemian' side that included him dressing like an artist, practicing the made-up martial art of Baritsu and having a heavy cocaine addiction.
At the premiere of Sherlock Holmes, Hollywood hell-raiser Robert Downey Jr. commented that reading Holmes' quirky side "could be a description of me" as the film went on to earn over $500m worldwide as Downey Jr won a Golden Globe for his performance as the detective.
Tobey Maguire as Spider-Man
One of the movies that kick-started the comic book movie boom of recent years was when Tobey Maguire donned the red and blue spandex suit to play Spider-Man all the way back in 2002.
When Maguire was announced as Peter Parker, fans stated that they didn't think he had the physique or wit to play Spider-Man.
Maguire sought the advice of a physical trainer, a yoga instructor, a martial arts expert and a climbing expert to improve his physique and get him in shape to play Spidey.
Upon its release, Spider-Man was widely-praised and fans turned around their opinion on Maguire as Peter Parker; two sequels followed before a reboot saw Andrew Garfield taking over as Spidey while fans now argue over who provided the best performance as the web-slinger.
Matt Damon as Jason Bourne
When The Bourne Identity director Doug Linman was looking for the right actor for his adaptation of Robert Ludlum's best-selling amnesiac spy-assassin, he approached Russell Crowe and Sly Stallone.
So fans of Ludlum's Bourne book series were understandably perplexed when Linman went for Matt Damon, whose performances had either been overly-sensitive (in films like Good Will Hunting and The Talented Mr. Ripley) or too childish (Dogma) to be taken seriously as an action star.
Three blockbuster Bourne films later, Matt Damon and Jason Bourne had become the same thing, which is why fans were so up-in-arms when Damon didn't return for The Bourne Legacy and fans had to cope with Jeremy Renner as a pale imitation.
It's no wonder that fans rejoiced when Damon returned for Jason Bourne earlier this year.