Is it normal for a law firm to leave their files out ??

I was at a law firm for some advice, as I walked pasted their glass door offices I saw files everywhere? I mean I’m sure there are some cases which are confidential or highly sensitive…

I made a joke and said it must be hard to pack away the files everyday have work. They simply reply ‘there’s no need.’

They are in a shared building with other businesses too, so the cleaners and building managers have keys to every office.

Is this what a professional law firm does??