I see a lot of recommendations for various services and products which are respect privacy, but I don't think I have seen any discussion around cell phone carriers (service providers). I am aware of some of the advantages of using VOIP as a phone service. However, if VOIP is not desired, what are good options for an US phone carrier which provides a physical SIM or eSIM?
I am guessing I have not seen this discussed because phone calls and SMS texts come with inherent insecurities and can always be associated to your phone number. However, I would assume some carriers sell users data more heavily than others. If anyone knows some recommendations, or can explain what to look for, many thanks.
The term "public record" usually refers to records that a government is required to maintain and make accessible to the public. In most states, I believe SMS messages sent by government employees while conducting official business are considered in-scope (though there may be other laws that make certain messages private).
As far as whether your SMS messages can be accessed by law enforcement without a warrant, it gets more complicated.
Older than 180 days? Fair game. A court or government agency can subpoena your provider without any requirement to notify you, per the Electronic Communications Privacy Act of 1986.
Newer than 180 days? A warrant is required, but there are exceptions. For example, administrative subpoenas are allowed in cases of national security.
Records of incoming/outgoing calls require only a subpoena, same with cell tower geolocation data and IP addresses. However, wiretapping of actual calls requires a warrant.
The reality of how and when the government accesses your data in the real world is probably different than the laws as written, so of course take everything with a grain of salt. The best solution with text messages is at least E2E encryption so that the provider cannot store them. (Accessing messages stored on your device itself does require a warrant).