Library privacy from the perspective of “groups”

I am trying to think of privacy from the perspective of the individual, the group, and society as a whole.

When it comes to “groups”, there are so many different types
Collective groups
Ascriptive groups
Ad-hoc groups

I am trying to figure out whether it is helpful or useful to think of privacy in relation to groups, particularly in a library context. Doing a bit of brainstorming, here’s a listing of different types of groups that I have come up with (some are clearly library-related, while others might be less obviously so):

Adult writers group
Biological group
BME/BAME group
Cultural group
Discussion group
ebook working group
Ethnic group
Family group
Focus group
Friends of the library group
Genealogy group
Information Assurance Group
Interest groups
Journals club
Knitters group
Library user group
Linguistic group
Lobby group
Marginalized groups
Patron privacy interest group
Peer group
Performing arts group
Political groups
Professional groups of librarians
Public library client groups
Reading group
Religious group
Social groups
Socio-economic group
Youth group
Vulnerable groups
-Domestic violence survivors
-Racial and ethnic minorities
-LGBT communities

What about “group” in the sense of a “legal personality” other than a natural person (a company, a trust, an association, a community benefit society, or in the case of The London Library, an organisation with a royal charter)

Thinking in terms of a “legal personality”, that could be:
the organisation running the library,
a library vendor,
or a third party.

Then a few thoughts about the nature of the group:
Common bond group (member attachment, based primarily on attachments among group members)
Common identity group (group attachment based primarily on direct attachments to the group identity)

Dynamic and fluid group
Stable group

Has common interest
Capable of joint action
Explicit common traits and purposes

Does the group’s identity survive even when there are changes to the individual membership constituting the group

Does the group have
Its own memories
Its own culture
Its own choices
Its own rites and customs