Traditionally defamation law has always held republishers of content liable for defamatory content they distributed, regardless of whether they authored the mat

Traditionally defamation law has always held republishers of content liable for defamatory content they distributed, regardless of whether they authored the material themselves. If you wrote a letter to the editor of a newspaper saying "P is a child molester", the newspaper printed and distributed it, and it wasn't true, P could sue not only you but also the newspaper for damages. This law was totally uncontroversial until the dawn of public electronic communications providers (pre-Internet, even) and automated republication systems like bulletin boards. That's why newspapers also continue to do useful things like fact checking.