Both sides of any litigation are obligated to produce all relevant materials in response to subpeonas from each other. This is what the discovery phase is all a

Both sides of any litigation are obligated to produce all relevant materials in response to subpeonas from each other. This is what the discovery phase is all about. The protection against unlocking someone's phone, laptop, etc. prevents the other side of the litigation from rifling through someone's device and going on a fishing expedition -- especially until the defendant can consult an attorney. Blatant fishing expeditions are not allowed. It does not allow people to hide evidence that is specifically requested as a part of a court ordered subpeona. Basically, if the other side requests a piece of information, you can't legally withold that evidence from the court. If the court discovers such behaivor they can sanction the non-compliant party (financial penalties for instance), issuing a negative inferrence (i.e. we'll just assume the worst about the material and make that a part of our decision), all the way up to issuing a default ruling (i.e. you lose). Trying to hide evidence is the quickest way to piss off a judge and you definitely don't want to do that. Judges do not take kindly to anyone who challenges the court's authority.