Possible to disable device lock without knowing the code [answered]
If the device lock is enabled there is a small, undefined grace-time where one can change Automated locking time, Number of tries and even Clear security code. I understand why it might be implemented this way, but I rather enter my security code each time I change any of these settings. After all, I don't tend to change these settings multiple times in one go.
I just imagined me unlocking the phone to show a "friend" a web page. He/she then clears the security code and enters a new one, just as a prank.