I'm progressive as they come, but that's not entirely true. While nowhere near as bad as any of the conservative justices, Sotomayor used her position of power to have her staff push book sales to libraries and schools, something that would be illegal for pretty much any other federal employee:

Sotomayor’s staff has often prodded public institutions that have hosted the justice to buy her memoir or children’s books, works that have earned her at least $3.7 million since she joined the court in 2009. Details of those events, largely out of public view, were obtained by The Associated Press through more than 100 open records requests to public institutions. The resulting tens of thousands of pages of documents offer a rare look at Sotomayor and her fellow justices beyond their official duties.

In her case, the documents reveal repeated examples of taxpayer-funded court staff performing tasks for the justice’s book ventures, which workers in other branches of government are barred from doing. But when it comes to promoting her literary career, Sotomayor is free to do what other government officials cannot because the Supreme Court does not have a formal code of conduct, leaving the nine justices to largely write and enforce their own rules.

https://apnews.com/article/supreme-court-sotomayor-book-sales-ethics-colleges-b2cb93493f927f995829762cb8338c02