Olmstead v. United States, 277 U.S. 438 (1928)
The reasonable view is that one who installs in his house a telephone instrument with connecting wires intends to project his voice to those quite outside, and that the wires beyond his house and messages while passing over them are not within the protection of the Fourth Amendment. Here, those who intercepted the projected voices were not in the house of either party to the conversation.The court went on to say that Congress could limit the right of the government to obtain evidence by warrantless wiretapping, but providing protection of telephone privacy was not the court's job.
As for Scalia, one need look no further than the Heller case to see how willing he is to adopt the statist mantle. Scalia is no friend of the government being ruled by the people.