[That-one-thing]

Well it's sort of true.

If you find a bad person and get someone to follow them with a really good camera you'll likely get the code (especially for a phone ). If you are at a mall in a high tech country I was told that you can read what they write on their phones ( No source, and if not think about the future ).

So you will need some police work but that's actually how it has been used for most part of the last hundred years, where you can't just look stuff up on a computer.

So yes there is no real guarantee that you can crack a phone. But if we learned anything from the dark markets it's that it's very hard to never makes mistakes.