Does the Fourth Amendment extend beyond the scope of criminal investigations?

"It is well settled that the Fourth Amendment's protection extends beyond the sphere of criminal investigations." City of Ontario, Cal. v. Quon, 560 U.S. 746, 755 (2010). "'The Amendment guarantees the privacy, dignity, and security of persons against certain arbitrary and invasive acts by officers of the Government,' without regard to whether the government actor is investigating crime or performing another function." Id. at 755-56 (quoting Skinner v. Railway Labor Executives' Assn., 489 U.S. 602, 613-14 (1989)). "The Fourth Amendment applies as well when the Government acts in its capacity as an employer." Id. at 756.