William O. Douglas,
United States v. Grinnell Corporation…
“ But there is here a single use, i.e., the protection of property, through a central station that receives signals. It is that service, accredited, that is unique and that competes with all the other forms of property protection. We see no barrier to combining in a single market a number of different products or services where that combination reflects commercial realities. To repeat, there is here a single basic service-the protection of property through use of a central service station-that must be compared with all other forms of property protection. ”
