It seems to me like a person could care about “these n people lacking privacy in this way” more than n times as much as they would care about any one of them marginally gaining or losing privacy in that way?

Or, idk if that is quite the right formulation for what I mean.

But, at the least, it seems likely that some people will sometimes be willing to take an amount of effort to protect the privacy of a large number of people, when they wouldn’t take that same amount of effort to just protect their own to the same degree.

It seems likely to me that a major impact of lack of privacy comes from many people lacking privacy, in ways that wouldn’t happen if it were only a few lacking it, and also where a few re-gaining it doesn’t influence the impact all that much.

If so, then people not avoiding something because of privacy concerns in sufficient numbers to substantially influence the amount of use, doesn’t seem to entirely rule out that they care about privacy. Perhaps their behavior could be attributed to a collective action problem, where they each would prefer that all of them avoid it, but don’t find it worthwhile to be among only a small number of people avoiding it.