[raphman]

Actually, it is the other way round - not the journalist has to know how much tampering has occured - I, the reader, have to trust the newspaper to get everything right in their reporting. Unlike in science, journalists often can not or do not want to reveal their sources and attribute every statement. Therefore, I need to be able to trust the newspaper as a whole that they have appropriate safeguards in place to detect and avoid false information and tampered images. By being holier than the pope, the newspaper supports this trust.