Taylor also commented on how the record label manager had been bullying her for years, referencing the incident where Kim Kardashian leaked a recording of a phone call between Kanye West and Swift.
The artist included an image of Justin Bieber's Instagram post from the time, which featured a screenshot of a Facetime call between Scooter Braun, Bieber and Kanye West and the caption "Taylor swift what up."
Swift also pointed out that Kanye West, (incidentally another one of Scooter Braun's clients) had featured her nude body in one of his videos.
"All I could think about was the incessant, manipulative bullying I’ve received at his hands for years.
"Like when Kim Kardashian orchestrated an illegally recorded snippet of a phone call to be leaked and then Scooter got his two clients together to bully me online about it. (See photo) Or when his client, Kanye West, organized a revenge porn music video which strips my body naked."
Taylor explained that she believes her music is in the wrong hands and that she was only 15-years-old when she made the mistake of signing with Scott Borchetta.
"Now Scooter has stripped me of my life’s work, that I wasn’t given an opportunity to buy. Essentially, my musical legacy is about to lie in the hands of someone who tried to dismantle it.
"This is my worst case scenario. This is what happens when you sign a deal at 15 to someone for whom the term ‘loyalty’ is clearly just a contractual concept. And when that man says ‘Music has value’, he means its value is beholden to men who had no part in creating it.
"When I left my masters in Scott’s hands, I made peace with the fact that eventually he would sell them. Never in my worst nightmares did I imagine the buyer would be Scooter.
"Any time Scott Borchetta has heard the words ‘Scooter Braun’ escape my lips, it was when I was either crying or trying not to. He knew what he was doing; they both did. Controlling a woman who didn’t want to be associated with them. In perpetuity. That means forever."
The artist signed off the Tumblr post by cautioning young artists engaging in negotiations with record labels.
"Thankfully, I am now signed to a label that believes I should own anything I create. Thankfully, I left my past in Scott’s hands and not my future. And hopefully, young artists or kids with musical dreams will read this and learn about how to better protect themselves in a negotiation. You deserve to own the art you make.
"I will always be proud of my past work. But for a healthier option, Lover will be out August 23.
Sad and grossed out,
Shortly after, Justin Bieber came to the defense of Scooter Braun through an Instagram post.
The 25-year-old shared a photo of himself with Taylor Swift, and initially apologised in the caption.
"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."
Justin then went on to defend Scooter Braun, accusing Taylor of being unfair and trying to rally her fans against the record label manager.
"I have to be honest though it was my caption and post that I screenshotted of Scooter and Kanye that said “Taylor swift what up” he didn't have anything to do with it and it wasn't 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."
The pop star signed off the post by stating that both he and the record label manager had a love for Taylor.
Justin also suggested talking in person to set aside any differences.
"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 forth online I don't 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."
Other artists and musical creatives have since come to the defense of Taylor Swift, including Halsey and Joseph Kahn.
Scooter Braun is yet to respond to Taylor's post, which has now created a #WeStandWithTaylor trend on Twitter.