(Revisiting when my thoughts percolated into more coherent words:) You don’t get to live in the convenient world where most potential blackmailers are people with good alternative options. It’s always going to be an adversarial sample; the people who are most likely to attempt blackmail are those with the worst alternatives and the lowest costs; the ones who have little or no reputation to lose, and poor returns on their effort if it’s directed in other directions. If you can’t deter someone with minimal reputation and low value of their time from blackmailing you, your only defense against blackmail is to prevent anyone meeting that description from having information they could use to blackmail you.
(Revisiting when my thoughts percolated into more coherent words:) You don’t get to live in the convenient world where most potential blackmailers are people with good alternative options. It’s always going to be an adversarial sample; the people who are most likely to attempt blackmail are those with the worst alternatives and the lowest costs; the ones who have little or no reputation to lose, and poor returns on their effort if it’s directed in other directions. If you can’t deter someone with minimal reputation and low value of their time from blackmailing you, your only defense against blackmail is to prevent anyone meeting that description from having information they could use to blackmail you.