Books and movies full of anti-vaccination conspiracy theories were found to have been dominating Amazon's online stores, raising concerns that the company prioritises free speech over public health.

A search for the word 'vaccine' on Amazon US returned books and movies dominated by anti-vaccination content, with 15 of 18 books and movies listed containing anti-vaccination content. 

These were published under titles such as 'We Don’t Vaccinate!' and 'Shoot ‘Em Up: The Truth About Vaccines,' as well as under more misleading titles like 'Miller’s Review of Critical Vaccine Studies: 400 Important Scientific Papers Summarized for Parents and Researchers,' according to CNN.

The finding prompted US Congressman Adam Schiff to complain to Amazon CEO Jeff Bezos that his company was serving up anti-vaccine propaganda and accepting paid advertising for anti-vaccine media.