The IMEI identifies a device. It is, or should be, useful to lock stolen phones, though it can obviously be used to track someone who keeps the same phone even if they change SIM card.
The IMSI identifies the subscriber (and/or the SIM card) even if you change phone.
As long as people are able to call and be called and as long as people need to be billed there has to be a reliable form of identification.
This is not an "intrusive privacy violation", it is, as you point out, a technical requirement of our willingness to be reachable and most people think that the benefits far outweigh the very limited drawbacks.
> As long as people are able to call and be called and as long as people need to be billed there has to be a reliable form of identification.
Secrecy of user nyms is trivially solved by existing mix networks (eg TOR onion services). Network access/billing could be solved by blinded signature tokens or some other untraceable bearer instrument. Implementing latter would take cooperation from the network provider, or at least an MVNO and SIM manufacturer, but it is indeed possible.
Username checks out. Unfortunately, truth is spoken.
This is the danger inherent to full enumeration of the technologically enabled envelope. This is also the danger of the "market"; as it incentivized the ability to clearly specify the "who" of the customer.
It's why I've been getting increasingly uncomfortable with the economic push away from cash as the primary medium of economic exchange.
The death of the payphone marked the beginning of the end for infrastructure that wasn't in some way dependent or useful as a means of user surveillance.
The IMSI identifies the subscriber (and/or the SIM card) even if you change phone.
As long as people are able to call and be called and as long as people need to be billed there has to be a reliable form of identification.
This is not an "intrusive privacy violation", it is, as you point out, a technical requirement of our willingness to be reachable and most people think that the benefits far outweigh the very limited drawbacks.