A furious Taylor Swift has ignited her latest celebrity feud via a social media takedown she wrote after her master recordings were sold to her nemesis, celebrity manager Scooter Braun.

“All I could think about was the incessant, manipulative bullying I’ve received at his hands for years,” Swift wrote on Tumblr about Braun.

“This is my worst-case scenario,” said the 29-year-old.

“Essentially, my musical legacy is about to lie in the hands of someone who tried to dismantle it.”

Swift’s reveal of the dark side of the music industry saw a deluge of more than 250,000 tweets of support and spawned the viral hashtag ‘We Stand With Taylor’.

On June 30 it was announced Braun’s media holding company Ithaca bought the rights to Swift’s back catalog of six albums from her old label, Big Machine Label Group, for $428 million.

Swift’s lengthy and emotional post also called out Justin Bieber, Kanye West and Kim Kardashian West, rehashing a bitter public war over West’s 2016 song Famous.

It featured him rapping, “I feel like me and Taylor might still have sex/I made that bitch famous” and its “revenge porn” music video stripped “my body naked”, Swift said in her letter.

Iggy Azalea, Allie X and Carlie Hanson rushed to give Swift props.

“Taylor Swift is a huge reason why I always insisted to write my own music. She deserves to own the painstaking labour of her heart,” said Bad at Love singer Halsey.

Bieber clapped back, defending himself and his long-time manager Braun on Instagram, chiding Swift for “crossing a line” while telling Swift “Scooter and I love you … we truly want the best for you.

“Scooter and I would love to talk to you and resolve any conflict.”

View this post on Instagram

Hey Taylor. First of all i would like to apologize for posting that hurtful instagram post, at the time i thought it was funny but looking back it was distasteful and insensitive.. I have to be honest though it was my caption and post that I screenshoted of scooter and Kanye that said “taylor swift what up” he didnt have anything to do with it and it wasnt even a part of the conversation in all actuality he was the person who told me not to joke like that.. Scooter has had your back since the days you graciously let me open up for you.! As the years have passed we haven’t crossed paths and gotten to communicate our differences, hurts or frustrations. So for you to take it to social media and get people to hate on scooter isn’t fair. What were you trying to accomplish by posting that blog? seems to me like it was to get sympathy u also knew that in posting that your fans would go and bully scooter. Anyway, One thing i know is both scooter and i love you. I feel like the only way to resolve conflict is through communication. So banter back and fourth online i dont believe solves anything. I’m sure Scooter and i would love to talk to you and resolve any conflict, pain or or any feelings that need to be addressed. Neither scooter or i have anything negative to say about you we truly want the best for you. I usually don’t rebuttal things like this but when you try and deface someone i loves character thats crossing a line..

A post shared by Justin Bieber (@justinbieber) on Jun 30, 2019 at 2:54pm PDT

Bieber’s involvement drew scorn from actor and model Cara Delevingne.

“I wish you spent less time sticking up for me and more time trying to understand women and respecting their valid reactions,” tweeted Delevingne to Bieber.

Actor Elaine Hendrix was another to have Swift’s back, channelling her The Parent Trap character Meredith Blake.

Me with anyone throwing shade at @taylorswift13. Literally me.
🔥😈#WeStandWithTaylor pic.twitter.com/YvYTPuCfnD

— Elaine Hendrix (@elaine4animals) July 1, 2019

taylor wrote an entire album BY HERSELF at 19… no co-writers… just her and only her… and now she doesn't even own the album anymore ?? thats so sick and twisted#WeStandWithTaylor

— L♡ #WeStandWithTaylor (@starlightsiyeon) July 1, 2019

me deleting taylor swift, fearless, speak now, red, 1989, and rep from my spotify playlist because i refuse to give scooter braun money:#WeStandWithTaylor pic.twitter.com/J7owPJPy8U

— L (@lcbiene_) July 1, 2019

Bieber’s semi-olive branch is unlikely to appease Swift, who said she learned Braun had bought her masters as it was announced to the world”.

The Shake It Off singer parted ways with Big Machine Label Group in 2018 when the 12-year contract she signed at age 15 ended.

In her Tumblr letter, she insisted she “pleaded for a chance” to own her work, but instead was offered a re-sign with the right to earn back an album for each new one released.

“I had to make the excruciating choice to leave behind my past.

“Music I wrote on my bedroom floor and videos I dreamed up and paid for from the money I earned playing in bars, then clubs, then arenas, then stadiums.”

Swift added that “never in in my worst nightmares” did she think her masters would be sold to Braun.

“Any time [Big Machine Records CEO] Scott Borchetta has heard the words ‘Scooter Braun’ escape my lips, it was when I was either crying or trying not to,” she said.

Braun’s wife Yael Cohen Braun, founder of health organisation F–k Cancer, also got involved by defending her husband on Instagram and urging Swift to “get her facts” straight.

“What you haven’t seen is what happens behind closed doors, when he has supported and stood up for you,” Ms Cohen Braun wrote to Swift.

“The world has watched you collect and drop friends like wilted flowers.”

View this post on Instagram

@taylorswift, I’m here to talk privately anytime.

A post shared by Yael Cohen Braun (@yael) on Jun 30, 2019 at 3:53pm PDT

Swift ended by saying her new label Republic Records is more supportive, and her masters from upcoming album Lover, dropping in August, will be hers to own.