If you (in this case parent) block something (in this case browsing porn sites) on some software (in this case Android device), it most definitely _is_ a security issue if the user (in this case a child) can bypass the restriction you imposed. I don't understand what's not clear there? If your phone is locked with a pin and you pass it to your friend (Stifler) because his mom just called you, he should not in any circumstance, be able to unlock your phone without knowing the pin code. That's the first issue. The second security issue is the possibility of any website calling private internal Android functions for (potentially) setting encryption keys of your device (!!!) You don't consider this a security issue?