Amazon has taken another step towards political censorship, banning all books by Dr. Joseph Nicolosi, a psychologist associated by critics with the rise of “gay conversion therapy.” This follows its ban on a book by Islam critic Tommy Robinson earlier this year.

According to LGBT news site PinkNews, the online retailer took action against Nicolosi’s books after repeated complaints by U.K. citizen Rojo Alan.

“Once I gathered everything I went back to Amazon and I threw all the information I had at them in several conversations,” Alan said. “Yet I was given the same ‘we will refer this to the relevant team.’” Alan last contacted Amazon on June 26. As of yesterday (July 2), all of the books by Nicolosi had been removed. “I’m currently in Starbucks, I’m so close to crying that all my efforts seem to have paid off,” Alan said.

This is the latest in an increasing trend of digital book-burning by Amazon, the company founded and owned by anti-Trump billionaire Jeff Bezos.

In February, the company banned several far-right, white nationalist authors. In March, the company went further, banning Muhammed’s Koran, a book by Islam critics Tommy Robinson and Peter McLoughlin highlighting violent passages in the Islamic text.

Ironically, the idea “gay conversion therapy” is often used by religious critics to allege that Christianity has a homophobic streak. But by banning Robinson’s book, the online retailer is protecting a religion linked to many modern-day acts of homophobia, like the execution of gays in ISIS-controlled territory and the Pulse Nightclub shooting.

As Breitbart News reported in April, there doesn’t seem to be any clearly defined principle behind the company’s piecemeal acts of censorship:

In 2010, Amazon refused to take down a book defending pedophilia on first amendment grounds. “Amazon believes it is censorship not sell certain books simply because we or others believe their message is objectionable,” an Amazon representative told CNBC at the time. “Amazon does not support or promote hatred or criminal acts, however, we do support the right of every individual to make their own purchasing decisions.” Public and media outcry was not enough to pressure Amazon into watering down its commitment to content-neutrality when it came to a pro-pedophile book. But it now takes only the slightest pressure for the tech giant to ban right-wing critiques of religion. And even before that, Amazon had watered down its commitment to “the right of every individual to make their own purchasing decisions.” In 2015, the site banned the sale of all merchandise depicting the Confederate flag. Amazon doesn’t seem to have a problem with extremist or destructive books in general. Two of the most destructive books in history, Adolf Hitler’s Mein Kampf and The Communist Manifesto by Karl Marx and Friedrich Engels are available for purchase. So too are books by black nationalist Louis Farrakhan, notorious for his racist and anti-semitic comments — so it seems racial hatred isn’t subject to a blanket ban on Amazon either.

Breitbart News will continue to report on Amazon’s censorship of books.

Are you an employee at Amazon or any other corporation who can obtain information about political bias within your company? Reach out to Allum Bokhari confidentially at allumbokhari@protonmail.com.

Allum Bokhari is the senior technology correspondent at Breitbart News.