Blackmail Fail: How I Refused to Pay Extortionists
Blackmail Fail (2013)
Gwern recounts several attempts to blackmail him over his online pseudonym, including a 2012 ransom for usernames on Pivory, a 2013 claim he was Dread Pirate Roberts, and a 2014 threat from Evolution. He explains his decision-theoretic argument for never paying, discusses the flaws in the extortionists' schemes, and shares his predictions and their outcomes.
Since there are indefinitely many Internet sites which allow user signups and publicly visible comments, accepting an extortion on any of them for any amount exposes me to indefinitely large losses.