I would imagine any searches would become available if subpoenaed in a lawsuit, as well. Say the searchee was actually stalked and injured/killed in real life. Any searcher would be questioned, at a minimum.
RE: I would imagine any searches would become available if subpoenaed in a lawsuit
So, why use Facebook at all? Life was simple and happy years before this company was born. We lived without it then, we can live without it now.