Four is unlucky in Japan because it is pronounced the same as "death".
The 4th Amendment protects people, not places. What a person knowingly exposes to the public, even in his own home or office, is not a subject of Fourth Amendment protection. But what he seeks to preserve as private, even in an area accessible to the public, may be constitutionally protected.
The 4th Amendment is a protection to people, not places. What he seeks to preserve as private, even in an area accessible to the public, may be constitutionally protected.

The 4th Amendment is often associated with the idea, deeply embedded in english common law, that a man's home is his castle.
The 4th Amendment is at it’s core, the right of a man to retreat into his own home and there be free from unreasonable governmental intrusion.
The 4th Amendment is on life support, largely because of the National Security Agency.
The 4th Amendment is grounded in the idea that it is better that the guilty sometimes go free than that the citizens be subject to easy arrest.