There's a different argument here. Some buildings keep a visitor log. That will say when I arrived, perhaps who I'm visiting, and likely when I left. I do not own that data, and it is not part of my papers.
Nor is this information part of the papers of the person I'm visiting. It's part of the business records of the building owner.
There's no promise that this information is private. Indeed, in some buildings it's often semi-public information, in that successive visitors can likely see the log when signing in or out, and it's left on the main desk all day.
The argument is that this information isn't under 4th amendment protection because it not not part of your private or personal information.
The recent court opinion by Judge Leon against the NSA points out - rightly, in my opinion - that when there is a lot of information about who you communicate with, then that in turn reveals information about you and your thoughts. You should read the opinion.
Nor is this information part of the papers of the person I'm visiting. It's part of the business records of the building owner.
There's no promise that this information is private. Indeed, in some buildings it's often semi-public information, in that successive visitors can likely see the log when signing in or out, and it's left on the main desk all day.
The argument is that this information isn't under 4th amendment protection because it not not part of your private or personal information.
The recent court opinion by Judge Leon against the NSA points out - rightly, in my opinion - that when there is a lot of information about who you communicate with, then that in turn reveals information about you and your thoughts. You should read the opinion.