Bloom threw a punch at Biebs in an Ibiza restaurant in July 2014, after which the singer screamed, "What's up, bitch?" The scuffle is widely believed to be over Bloom's then-wife Miranda Kerr, with whom Bieber was seen getting close at the 2012 Victoria's Secret Fashion Show. In April 2014, Bloom was photographed with Bieber's on-again, off-again girlfriend Selena Gomez. After the fight, Bieber posted a bikini-clad photo of Kerr on Instagram before deleting it.

Prinze, who recurred on the eighth season of 24, blasted Sutherland in 2014 for being "the most unprofessional dude in the world." Prinze's experience on the show was so bad that he "just wanted to quit the business after that." Sutherland's rep took the high road in response: "Kiefer worked with Freddie Prinze Jr. more than five years ago, and this is the first he has heard of Freddie's grievances. Kiefer enjoyed working with Freddie and wishes him the best."

Rapper T.I. reportedly confronted pro boxer Floyd Mayweather Jr. inside a Fatburger restaurant on the Las Vegas Strip, and their argument quickly turned physical. At least one chair was picked up and thrown. (Neither was seriously injured in the fight, although the same can't be said for an unlucky Fatburger employee who was slashed after being caught in the middle.) The issue? T.I. was reportedly upset that his wife, Tiny, had posted photos on Instagram of herself hanging out with Mayweather. For his part, Mayweather said he has no interest in Tiny romantically and that he was shocked T.I. attacked him.

Oh, Twitter, where would celeb feuds be without you? After Charlie Sheen discovered that Rihanna was at the same Santa Monica eatery as he and his fiancée, the actor sent a request that the "Don't Stop the Music" singer meet them, which she promptly refused. Miffed by the diss, Sheen took to Twitter, and the two traded insults over bad wigs and diapers and called each other "village idiot" and "queen." Sheen capped off his attack with a poem, as he is wont to do, with the creatively spelled "doosh" (aka douche). Will Rihanna respond in kind to the fella, ella, ella, ella?

Barr took to Twitter to accuse the Two and a Half Men creator his writing staff of lifting jokes from her stand-up routine. Ironically, Lorre got his start as a supervising producer on Roseanne in the 1990s, but there's clearly no love lost between the former colleagues. "I need to do like Chuck Lorre's writers do — watch some stand up and steal some jokes for my new scripts. I could produce ten shows, maybe!" Barr tweeted. (Others were much more colorful.) Lorre has yet to respond publicly to the tweets, but for now, consider this bridge burned!

After Cyrus said O'Connor's "Nothing Compares 2 U" inspired her single "Wrecking Ball," the Irish singer posted an open letter to the former Hannah Montana star. Criticizing Cyrus' video for the song, O'Connor said that getting naked is not a way to gain respect as an artist. Cyrus responded by comparing O'Connor to Amanda Bynes and posting old tweets of O'Connor seeking psychiatric care, which prompted O'Connor to demand Cyrus apologize to Bynes and remove her tweets or else she'd pursue legal action.

From Kanye West's notorious interruption of Swift's acceptance speech during the 2009 MTV Video Music Awards to implying that Tina Fey and Amy Poehler are going to Hell for joking about her at the Golden Globes, trouble follows Swift everywhere she goes. That's not to mention her multiple dating dramas, most notably her ongoing issues with ex-fling John Mayer. Though Swift and Mayer haven't been together since 2010, the singer was allegedly "irked" by his mere presence at the 2013 Academy of Country Music Awards and demanded that she go on before him. But this is all just fodder for her next hit song, right?

After The Black Keys' Patrick Carney dissed the Biebs' musical talent, Bieber replied that the drummer needed to be "slapped around." Carney revamped his Twitter account to mimic Bieber's and unleashed a series of sarcastic tweets mocking the singer's fans. Drake Bell also used Twitter to call out Beliebers and taunt the pop star, prompting multiple death threats to be sent Bell's way.

Chef Tony isn't shy with his words, and in 2011, he called Deen (who's known as the Butter Queen) the "worst, most dangerous person in America" for promoting her fattening recipes to an already obese nation. Shortly after, when it was revealed that she had been hiding her Type 2 diabetes diagnosis for several years, Bourdain said, "When your signature dish is hamburger in between a doughnut, and you've been cheerfully selling this stuff knowing all along that you've got Type 2 diabetes ... It's in bad taste if nothing else."

These musical superstars can't do anything on a small scale, can they? Their enmity began way back in 2002 when John criticized Madge's "Die Another Day," saying "It hasn't got a tune." Since then, he has consistently bashed her lip-synching and career choices while claiming to still be a fan of her music. In summer 2012, John called Madonna a "nightmare" who dressed like a "fairground stripper." Through the years, the Material Girl has turned the other cheek, but after that stripper jab, she cheekily dedicated her song "Masterpiece" to him. That's the same song that beat out John's "Hello Hello" for a Golden Globe.

American Idol lined up a Battle of the Divas for its 12th season — and no, we're not talking about the contestants. Even as the auditions were being filmed, it became clear that having both Carey and Minaj on the judges' panel was not going to go smoothly. In one infamous video, Minaj cursed out Carey for being too much of a princess, and during a press day leading up to the new season, Carey wouldn't compliment her fellow judge when asked to do so. Thankfully, the show's leading ladies have kept their animosity (mostly) in check during the live shows, instead opting to just ignore each other's presence most of the time. But it's likely one or both of them will be gone by next season.

When Charlie Sheen lost his mind in 2011, he also lost his job. The Two and a Half Men star went on multiple rants in which he attacked the showrunner Lorre, calling him a "clown" and a "p---y punk that I never want to be like." Sheen's behavior ultimately lead to his firing from the series, with his character suffering a grisly death. We guess Lorre got the last laugh?

Rimes and Glanville's then-husband, Eddie Cibrian, began an affair in 2009 and left their respective spouses for each other before marrying in 2011. However, when Rimes referred to Glanville's two sons with Cibrian as "my boys," the war really started. Glanville called Rimes "unstable" and "not healthy" in Us Weekly in addition to alleging her son got sick from eating laxatives belonging to Rimes, who called the allegations untrue and "mean-spirited." Since releasing her memoir, Drinking & Tweeting: And Other Brandi Blunders, Glanville has publicly declared she's done talking smack about Rimes, but we'll believe when we hear it. Or, rather, when we don't.

Can you think of two people more outspoken in their hatred for one another? O'Donnell and Trump have been trading barbs for years, attacking each other personally and professionally. Though after O'Donnell suffered a heart attack in 2012, Trump reached out and said "get better fast. I'm starting to miss you," to which the comedian jokingly asked if he was "trying to kill" her. Of course, now that O'Donell's better, the feud is back on in full-force.

In June 2012, Brown and Drake were involved in a now-infamous nightclub brawl, supposedly over Drake's past relationship with Brown's off-and-on girlfriend Rihanna. The pair continue to diss each other whenever an opportunity presents itself. That is, except when Brown turns his attention to Ocean. The singers got into an altercation over a parking space, during which Brown allegedly punched Ocean, though Ocean refused to press charges.

As much as Bynes loves Drake (or so she tells us on Twitter), the actress hates Perez Hilton. In addition to threatening to sue him, Bynes has repeatedly attacked the celeb blogger on Twitter, even going so far as to say he "makes being gay look bad." Despite Bynes' provocation, Hilton continues to beg his former friend to get help and wishes her well. Of course, that still hasn't stopped him from detailing her latest antics on his blog, which might not be the most "helpful" move.

They say don't bite the hand that feeds you, but that didn't stop Chase from walking off set and leaving an expletive-riddled voice mail for Community showrunner Harmon. Of course, Harmon isn't completely innocent in the events. He allegedly incited Chase's wrath after giving a "f--- you, Chevy" speech at a the show's wrap party in front of the actor and his family. But even after Harmon was fired, Chase continued to cause trouble, dismissing the show by calling sitcoms "the lowest form of television" and using the N-word on set. Chase has since left the series on reportedly mutually amicable terms with the production.

While most lauded Cooper for coming out in 2012, Jones felt a bit differently. The former View host called Cooper's admission a ratings ploy, inspiring a fiery back-and-forth between the pair. Cooper eventually decided to take the high road and end the feud (at least publically). "I've got nothing more to say, nor do I want to be in a room with her. I'm done," Cooper said.

Cole was happy to compliment Queen Bey during the Destiny's Child's Super Bowl reunion, though she was quick to insult bandmate Williams. "She's always f---ing the groove up," Cole tweeted in February. But only one month later, Cole turned on Beyonce, calling her "self-righteous" and questioning the motives behind her new single "Bow Down." Watch out, Kelly Rowland. You're up next!

It's no surprise that Jennifer Aniston's BFF isn't a big fan of Jolie. Over the years, Handler has repeatedly insulted the actress, calling her everything from a "homewrecker to "f---ing c--t" and "demon." While Angie used to carry a vial of blood around her neck, that doesn't necessarily mean she's satanic! If someone wants to insult Jolie with something from her past, at least make it about her brother-loving.

Such musical superstars as Madonna and Billy Joel have given Glee unprecedented access to their catalogues, but not Kings of Leon, who wouldn't allow the Fox musical rights to their songs. In January 2011, Glee co-creator Murphy publicly blasted the rock group in The Hollywood Reporter, calling them "self-centered a--holes" who "hate on arts education." It didn't take long for the group's drummer, Nathan Followill, to fire back on Twitter, where he recommended Murphy see a therapist and "zip your lip." Murphy eventually waved the white flag in April and said he regretted making their battle public.

Shia LaBeouf's Broadway debut is on hold for now after he quit (or was fired from) the play Orphans less than a month before its opening due to personality clashes with co-star Alec Baldwin. Both Baldwin and LaBeouf have kept up their war of words in the press, with LaBeouf speculating that Baldwin got him fired, and Baldwin saying LaBeouf's attitude problem and immaturity made it impossible to work with him. What's that saying about no crying in show business?

Since crossing over to America in 2012, these British boy bands have gotten into Twitter wars not once, but twice. In true teeny-bopper fashion, the insults exchanged were hilariously banal, including everything from "sass master" to "chlamydia boy" and allegations of bed-wetting. However, One Direction's Louis Tomlinson took the crown for best comeback, telling Tom Parker of the (much-less famous boy band) The Wanted, "P.S. enjoy the press from this."

Back in the day, Christina Aguilera gained attention for calling Osbourne fat, but now that Osbourne's trimmed down, she's turned the tables on the former Voice coach. For someone who's undergone such intense physical scrutiny herself, you'd think Osbourne would learn how hurtful comments like that are. Unfortunately, that hasn't stopped Osbourne from also calling Lady Gaga a butterface and jokingly asking if she was pregnant. Gaga refused to play along, writing an open letter to the star and asking for a ceasefire.