What kind of security features does iOS have to prevent a thief from re-selling my phone. I used to work in MDM, I feel like I've only got half the picture of how this works. If you reset the phone and there's no sim card inside, does it require to activate? What if it's unlocked? Can it be locked to an account so it turns into a brick after it's stolen? At work we used these 'blank sims' to bypass the SIM activation. I would like to know about the security features so I can protect myself better if something bad does happen.