We often discuss the deafening silence of professors and writers in the face of campaigns to cancel or censor conservative writers. Indeed, many have supported blacklisting and censorship. That disturbing silence is evident this week after Amazon appeared to deplatform Ryan Anderson and his best-selling book, “When Harry Became Sally: Responding to the Transgender Movement.” Now various conservative sites are objecting that a documentary on conservative Justice Clarence Thomas has been reportedly removed from Amazon’s streaming service — a glaring omission during Black History Month. Amazon has not responded to inquiries as to why the Thomas documentary is no longer available, so it is not clear if this was an intentional or negligent act. Given the controversy over the Anderson book, the sudden unavailability has triggered objections.