Will Smith has been targeted by people on social media for his new film Concussion, in which he plays the real-life Dr. Bennet Omalu, a Nigerian forensic pathologist who was the first person to diagnose a brain damage condition in NFL players.
Smith's attempts at copying Dr. Omalu's Nigerian accent has been mercilessly mocked, and he has found himself amongst the actors who tried to put on an accent and failed completely.
But is his accent the worst that's ever been heard in a film? Probably not when you consider some of these...
Charlie Hunnam in Green Street - London
Charlie Hunnam, born in Newcastle, already boasts one of the strangest transatlantic accents in entertainment, if you were to attempt to localise his real-life accent, you'd guess: "erm, is he from an American theme park version of Victorian England?"
When Hunnam starred in Green Street as a 'cheeky cockney football hooligan', his already-mangled accent couldn't extend itself to sounding like he'd wandered over from the EastEnders set.
Fortunately, the film was largely ignored, so Hunnam was able to (almost-successfully) attempt an American accent in Sons of Anarchy and Pacific Rim.
Sounds like: An Australian doing an impression of Benedict Cumberbatch
Anne Hathaway in One Day - Yorkshire
Trying to emulate Bridget Jones, Anne Hathaway starred in British rom-com One Day as Emma Morley, hailing from Leeds, as the film shows her and romantic interest Dexter on the same day each year.
Hathaway confessed that she learnt her accent from watching episodes of Emmerdale, while her accent was more an upper class South of England type that a "ey up, chuck" local accent.
Hathaway explained: "One of the things I was struck by was that so often when people leave Yorkshire they don't hang on to the accent, the accent evens out and starts to mimic some new sounds from where they're from, so you can have 10 people from Yorkshire and they have 10 completely utterly different accents."
Which isn't true in the slightest
Sounds like: An Oxbridge student having 'discovered herself' after her gap year in America
Brad Pitt in Seven Years in Tibet - Austrian
Brad Pitt played Austrian Heinrich Harrer in the true story of the mountain climber who became friends with the Dalai Lama.
Pitt's attempts at a the Austrian accent were widely derided and, in a career of poorly-executed accents, stands out as possibly his worst.
Sounds like: A Dutchman trying to do an Indian accent
Morgan Freeman in Invictus - South African
Hollywood icon Morgan Freeman took on the mammoth task of playing real-life icon Nelson Mandela in 2009's Invictus, about the South African President's bid to unite the apartheid-torn country with the help of the World Cup-winning rugby team.
Watching video tapes, Freeman tried to perfect Mandela's accent and speaking rhythm to emulate the legendary South African president, but struggled to escape the fact that his voice sounded like Morgan Freeman.
Sounds like: An impressionist who hasn't quite mastered his Morgan Freeman yet
Russell Brand in Rock of Ages - Birmingham
Russell Brand's portrayal as Lonny Barnett, the Brummie sidekick of club owner Dennis Dupree in the adaptation of the Broadway musical, it was the first time he was required to put on an accent.
Going for the Birmingham accent, it tended to move around England, which drifted to Liverpool, with a heavy sprinkling of his native London accent.
Sounds like: Every British inductee to the Rock and Roll Hall of Fame, at the same time
Juliette Binoche in My Country - Afrikaans
Academy Award nominated French actress Juliette Binoche took on the role of Afrikaner poet Anna Malan, who, alongside an American journalist, reports on the South African post-apartheid human rights hearings.
Not being a native English speaker, Binoche had double the challenge in speaking English and speaking it in an Afrikaans accent.
No-one would be surprised that her accent was "rubbish at best" as the film failed in the box office, but Nelson Mandela, who was given a private screening, enjoyed it... so it has that going for it.
Sounds like: A French woman doing her impression of Morgan Freeman in Invictus
Angelina Jolie in Alexander - Greek
In Oliver Stone's telling the story of Alexander the Great, main star Colin Farrell was unable to change his heavy Irish accent, so Val Kilmer and other cast members spoke with Irish accents... to confuse the audience?
Angelina Jolie was nominated for a Razzie for Worst Actress in this debacle, starring as Queen Olympus, Alexander's mother.
Seemingly unable to put on a Greek or Irish accent, Jolie went for an unconvincing Russian/Soviet Bloc accent to heap on the confusion.
Sounds like: A Cold War-era femme fatale in a James Bond parody
Josh Hartnett in Blow Dry - English
The world of competitive hairdressing was given its chance to shine in this British 'comedy' film starring Josh Hartnett, alongside Alan Rickman and Natasha Richardson and set in Keighley, a small town on the outskirts of Bradford.
Hartnett plays a local barber whose father is aiming to win the British hairdressing championship, held in Keighley, for some reason.
Despite the film being remembered by no-one, including the few people that saw it, Josh Hartnett's accent is still being laughed at.
It would seem that Hartnett wasn't quite able to nail the Yorkshire accent, so instead went for some form of questionable British accent.
Sounds like: An episode of Byker Grove performed by Scottish alcoholics
Don Cheadle in the Ocean's trilogy - cockney
While making Ocean's Eleven, Don Cheadle wanted his character to stand out from the star-filled line-up, how did he do this? By requesting that his munitions expert Basher a cockney.
The Missouri-born actor gave the 'cheeky cockney criminal' act a sporting try, aided by the writers sticking in every piece of cockney slang they heard when they watched Lock, Stock and Two Smoking Barrels.
Cheadle was widely-mocked for his accent, but that didn't stop him persisting with it in two more Ocean's films, which became an unintentional comedy highlight in the sequels.
Sounds like: Dick van Dyke's less talented brother in a film directed by Guy Richie's less talented brother
Jon Voight in Anaconda - Paraguayan
The tongue-in-cheek Creature Feature that boasted a surprisingly high-profile cast (Owen Wilson, Jenifer Lopez, Ice Cube, Danny Trejo) and Jon Voight as a Paraguayan snake hunter.
Originally, the part was set to go to French Leon: The Professional actor Jean Reno, who might have been able to put on a semi-decent Spanish accent, but the casting director must have been wowed by Voight's stinking South American accent.
Trying to one-up Al Pacino's Cuban accent as Tony Montana in Scarface, Voight failed dismally in the forgettable and ultimately crappy film.