I feel like I'm ok with Amazon execs needing to not auto-delete their messages when the FTC is doing discovery about anti-competitive practices ... but how far

I feel like I'm ok with Amazon execs needing to not auto-delete their messages when the FTC is doing discovery about anti-competitive practices ... but how far down does that go? - can a smaller or privately held company being sued be obligated to keep all their communications in a form which can be subpoenaed? - is a family business being sued under the same obligation? What if execs in that family business have both personal and business conversations? - is an individual being sued under the same obligation? - if I want access to someone's personal messages, can I contrive a reason to sue them, and create such an obligation to deliver personal correspondence to my counsel? - if Senator McCarthy thinks you're maybe a communist, can he publish your name as part of a list of suspicious persons and provide legal funds for to any wannabe vigilante who can contrive a suit against you? At some point, I think we as a society need to agree on what rights to privacy exist, how solid they are, which rights are enjoyed by individuals and which rights if any also apply to corporations.