> telco's who have to track everyone in order to comply with subpoenas.
Subpoenas are used to compel production of existing information. Speculatively creating info to comply with future theoretical request is not necessary. It's easier to not have the info and truthfully respond to subpoena with "no such data".
In the UK they are legally required to keep the data in order to respond to law enforcement requests. My understanding is that in the US they’re not required to, but at least the ones I work with do for whatever reason.
Subpoenas are used to compel production of existing information. Speculatively creating info to comply with future theoretical request is not necessary. It's easier to not have the info and truthfully respond to subpoena with "no such data".