Actually, the SIM card use to be a “personality chip” in the 1990s. It stored your phone number and your contacts. There’s a scene in The Wire where a drug dealer confuses the police by changing the sim card of his phone when talking about criminal activity, which evades electronic surveillance (changing the phone’s ID on the network) and physical surveillance (sims are very small and concealable). I was specifically calling out how the use of a cell has grown in the last 30 years specifically as it related to identity.

I’ve spent a lot of time engineering login pages and thinking about questions of user identity.