Yes, but as I moved between countries and bought SIM cards from many carriers all carrier employees offered me to disable the pin "for convenience". Let's say y

Yes, but as I moved between countries and bought SIM cards from many carriers all carrier employees offered me to disable the pin "for convenience". Let's say your phone died, and you put it on a charger. A phone would eventually turn itself back on, but if your sim is locked you. wouldn't be able to accept incoming calls until you unlock the phone and unlock the phone. Without a sim pin once your phone turns on you become available again. People like that. Also, even if you want to keep the pin on many people would set it to something convenient like 1111 or 9999. In fact, one of the carriers I used had 1111 s a default pin code for all their SIM cards. So, while security is there in theory, in practice it's rarely in place.