If I know your pseudonym, I can pretend to be you. For pseudonymous reporting to work therefore requires the reader to trust the publisher, who supposedly knows

If I know your pseudonym, I can pretend to be you. For pseudonymous reporting to work therefore requires the reader to trust the publisher, who supposedly knows the author. But in many countries (e.g. Colombia, where I live) it's reasonable to anticipate someone using the threat of violence to extract a reporter's identity.