It's good to have an option like that, even being a default, but there definitively need a switch to disable that if it is your own will.<p>It's not even necessarily that good enough against cops, because in a lot of shitty countries, even some pretending to be democratics, not disclosing or at least inputting your password might be a crime severely punished.
If I'm not wrong, there was a guy that had to stay years in jail until he would comply with the judge order to unlock his device.