A letter sent to a celebrity that is published in a public forum, rather than simply mailed. Open letters are almost always editorials about a recent action taken by the 'recipient' that the writer finds objectionable. They also tend to degenerate into ad hominem attacks poorly disguised as appeals for reason. These open letters tend to get published in forums that have never been visited by the 'recipient'.

When done well, an open letter can goad a response out of the recipient that would otherwise not be forthcoming.