Where does the line fall between cultural appreciation and cultural appropriation? Does it even exist when it comes to personal style? And if so, how big is the margin of error for famous people, specifically?

The question of whether or not it's okay for white people to wear dreadlocks (or cornrows or afros or any other black hairstyle, for that matter) is polarizing, nuanced, and seemingly impossible to reach a consensus on.

Even just a cursory look at the historical context surrounding this issue could – and does – fill many books. In the past four months alone, more than 770,000 headlines containing the term "cultural appropriation" have been archived by Google, along with millions of posts on Facebook, Twitter and other social networks.

Simply put, racial hair politics are a lot bigger than Justin Bieber. But, as the most-recent celebrity to take heat for wearing dreadlocks in the name of fashun, Bieber is where we begin.

The Canadian-born pop star debuted his new platinum blond locs on Sunday both at the iHeartRadio Music Awards in Los Angeles and to his fans on Instagram.

The ensuing wave of internet rage crashed fast and hard, giving way to dozens of biting thought pieces within just 24 hours of Bieber's original post.

In the video above, shot backstage at the awards show, the singer appears to be having a conversation with rapper Big Sean about how people were reacting to the hairstyle choice.

"[People say] you wanna be black and all that stuff," reads the video's transcription. "I'm like 'its just my hair'."

But, as critics were quick to point out, it's not just hair to those who wear dreadlocks for cultural, political or religious reasons. Rastafarians in Jamaica for many years faced discrimination based on their appearance, for example.

It's not "just hair" for men and women who've been fired, sent home from school and even physically assaulted over what's on their own heads, either.

"When black people wear these hairstyles that we've worn for decades, we catch flak for them," says Yesha Callahan, a writer and editor for the massively-popular African-American news outlet The Root, to CBC News. "But when white people wear them, they're occasionally considered trendy or 'trendsetters."

She points to the discrepancy in how hairstyles are received when worn by "culture vultures" like the Kardashians and Bieber, and the controversial remarks made by Fashion Police host Giuliana Rancic after actress Zendaya Coleman wore fake dreadlocks to the 2015 Oscars.

"When Zendaya Coleman wore even fake dreadlocks, [Rancic] said she looked like she smelled like patchouli and smoked weed," she told CBC News. "After the Kardashians started wearing cornrows, Kim Kardashian renamed them 'Kim Kardashian style braids' – so it's trendy now."

Kim K and her younger sisters are indeed responsible for one of the hottest hair trends in existence right now – and Callahan is far from the only person who's called out the reality TV star's "boxer braids" for what they really are.

"No one is saying that black people are the only people who can wear dreadlocks," she continued. "But there are people who just do it for a fad… who take aspects of other peoples' cultures because they think its stylish… who disregard the historical and cultural context of a style."

Of course, the Kardashian / Jenner braids and Bieber dreadlocks are just a few of many, many racially-charged hair controversies to emerge from the worlds of pop culture and fashion in recent years.

From music festivals selling First Nations-style headdresses as fashion accessories to Marc Jacobs passing off bantu knots as "mini-buns," there's been no shortage of fodder for angry (in many cases, justifiably so) blog posts about cultural appropriation this decade.

Just last week, the "white people with dreadlocks" controversy came to yet another head when a video shot at San Francisco State University, in which a black student is seen confronting a white student about his hairstyle, went viral.

While Callahan, who covered this story for The Root, believes that the white SFSU student had an understanding of and respect for dreadlocks, she doesn't suspect the same is true for Bieber. 

"Justin Bieber can probably care less that Vikings wore dreadlocks, or that East Indians wore dreadlocks, or about any other ancient culture who wore their hair that way," she told CBC News. 

That said, she isn't upset by the pop star's hair – however he chooses to style it.

"I personally don't have any issue with people wearing dreadlocks," she said. "When it comes down to it, you wear your hair how you want to wear your hair. It's not my hair, it's not growing out of my scalp."

Either way, she says, it's likely a short-lived look for the Biebs: "Next week, I'm pretty sure he won't have these dreadlocks."