The Supreme Court case Olmstead v. United States from 1928 is very famous for the dissenting opinion written by Justice Louis Brandeis.
However, it easy to misquote Brandeis by saying he wrote “the right to be left alone-the most comprehensive of rights and the right most valued by civilized men.” For example, sometimes the mistake is made in library science documents.
However, the actual quote is “the right to be let alone….” not “left alone.” The difference is substantial.
“Left alone” refers to things that directly affect a person. Generally, a violation of this definition would be known to the person whose privacy was violated. When the police come without a warrant looking for contraband, that would violate the principle of being left alone.
“Let alone” makes irrelevant whether there is the knowledge of the violation by the victim or whether they are directly affected. When the police use a Stingray to capture cell phone information, that is a violation of being let alone, but it isn’t a violation of being left alone.