title: iPhone - Detecting SIM card availability
body: <p>I am using the answer in this topic. <a href="https://stackoverflow.com/questions/8161235/iphone-how-to-determine-carrier-of-the-device-att-verizon-etc/8161253#8161253">iPhone - how to determine carrier of the device (AT&amp;T, Verizon, etc?)</a> which is the same as <a href="https://stackoverflow.com/questions/5204121/getting-operator-details-in-iphone">getting operator details in iphone</a>. Although it works fine when using a sim card, the returned carrier name if there is no SIM card is the old carrier name. It doesn't detect that the SIM is removed.</p>
  
  <p>I know this contradicts with Apple documentation that if there is no carrier, CTCarrier object shall be nil. But in my app I logged the carrier info and it gives me the latest carrier name although no sim is installed.</p>