You can separate the ability to reinstall the operating system from the ability to derive the keys to decrypt a particular device (or to instruct a running device to give you root). I think this is described in Frank Stajano&#x27;s <i>Security for Ubiquitous Computing</i>.<p>Edit: previously in his paper with Ross Anderson  <a href="https:&#x2F;&#x2F;www.cl.cam.ac.uk&#x2F;~fms27&#x2F;papers&#x2F;1999-StajanoAnd-duckling.pdf" rel="nofollow">https:&#x2F;&#x2F;www.cl.cam.ac.uk&#x2F;~fms27&#x2F;papers&#x2F;1999-StajanoAnd-duckl...</a><p>My ThinkPad can easily be reinstalled with a new OS, but my OS vendor can&#x27;t give someone else my full-disk encryption keys or make them root on my device. And even with firmware-level security features we can separate &quot;transfer ownership of device&quot; from &quot;access existing protected device state&quot;.<p>I don&#x27;t see any more reason that mobile phone vendors must be able to bypass screen locks or disk encryption than that desktop OS vendors must be able to do these things. (Sure, in both cases some users would want the vendor to be able to and others wouldn&#x27;t.)