I don't know anything about this prisoner, but I am upset to learn that prisons don't accommodate vegan diets--just vegetarian ones.  That seems to be true of The San Francisco Chronicle's Food and Wine section too.  This is true in spite of the fact that vegan diets are much kinder to the environment than diets with animals or animal products and of course they're better in alleviating the suffering of animals in factory farms.  

Magistrate Judge Sarah Netburn, presiding over Tuesday's hearing, told Bankman-Fried's attorneys that she would not overrule Kaplan's rulings about access to computers, but that she would see if she could get the Metropolitan Detention Center in Brooklyn to provide medications and a diet more closely aligned to the defendant's vegan preferences.

https://www.nbcnews.com/news/us-news/sam-bankman-fried-living-bread-water-jail-wont-abide-vegan-diet-lawyer-rcna101231

Magistrate Judge Sarah Netburn said she doesn’t think the prison can offer vegan, only vegetarian, and she said she would look into the situation right away. Bankman-Fried is currently held at the Metropolitan Detention Center in Brooklyn.