What are the implications of the Fourth Amendment when it comes to the search and seizure of electronic communications?

"The protections of the Fourth Amendment are of a wholly different order, and have nothing whatever to do with promoting the fair ascertainment of truth at a criminal trial.... The guarantees of the Fourth Amendment stand 'as a protection of quite different constitutional values--values reflecting the concern of our society for the right of each individual to be let alone....' [Citation.] [p ] Nor can it even be said that a search, as opposed to an eventual trial, is somehow 'unfair' if a person consents to a search.... [T]here is nothing constitutionally suspect in a person's voluntarily allowing a search.... And, unlike those constitutional guarantees that protect a defendant at trial, it cannot be said every reasonable presumption ought to be indulged against voluntary relinquishment." (Schneckloth v. Bustamonte, supra, 412 U.S. at pp. 241-243, 93 S.Ct. at pp. 2055-2056.)