Even surveillance of legal activities can inhibit people from engaging in them. The value of protecting against chilling effects is not measured simply by focusing on the particular individuals who are deterred from exercising their rights. Chilling effects harm society because, among other things, they reduce the range of viewpoints expressed and the degree of freedom with which to engage in political activity.
This is an aspect discussed in “‘I've Got Nothing to Hide' and Other Misunderstandings of Privacy“
https://papers.ssrn.com/sol3/papers.cfm?abstract_id=998565
Even surveillance of legal activities can inhibit people from engaging in them. The value of protecting against chilling effects is not measured simply by focusing on the particular individuals who are deterred from exercising their rights. Chilling effects harm society because, among other things, they reduce the range of viewpoints expressed and the degree of freedom with which to engage in political activity.