I think the concerns over privacy online are overblown for many people but I try to be smart about what I do and put online. So I think part of it might be the

I think the concerns over privacy online are overblown for many people but I try to be smart about what I do and put online. So I think part of it might be the framing of the situation. Rather than trying to convince them that they do actually have something to hide, it might be more effective to try to convince them that their attitude should be more like, "Don't put anything online that you don't want everyone to know" and also explain that there are people who do worry about things like people who have been in abusive relationships, people who might be in places where not being straight and cis gendered is not accepted and so on. I think it might also be good to ask yourself, "What do I want to accomplish by convincing this person to be concerned about online privacy?" and think about ways to accomplish that goal.