I'm quite positive (not a lawyer) that unlocking records (e.g. phone, phone book, laptop etc.) is not part of any legal search and under purview of wiretapping

I'm quite positive (not a lawyer) that unlocking records (e.g. phone, phone book, laptop etc.) is not part of any legal search and under purview of wiretapping or seizure laws, much less privacy laws. Those require a court order in general unlike a typical police search... unless CBP has leeway there too in which case it is a monster.