The statement “I’ve nothing to hide” is a clear and simple statement of privilege. It says that one is currently totally in line with existing culture power structures, that one is not a minority, or marginalized, or being sought by security forces. Privileged individuals who have no fear of persecution by cultural power structures are usually content to conduct their affairs in the open. These people have a moral obligation to use their privilege to help those who’re marginalized and in the minority, use secure services, encryption and so on to provide cover traffic for the rest.
Yup, this exact thing.
And it can be very hard to know ahead of time what needs to be hidden. Like, say, do you wear glasses? Because if so, you’re on the list, just ask Pol Pot.