The "pervasiveness" doctrine has been characterized as a "ticking time bomb" for free speech.

Never yet used by itself, pervasiveness often joins scarcity as an excuse for censoring broadcast media. The doctrine was first used in the 1920's with regard to radio. Secretary of Commerce Herbert Hoover said, "We can protect the home by preventing the entry of printed matter destructive to its ideals but we must doubleguard the radio." President Coolidge added that "there is an opportunity for greater license even than in the use of print, for.... radio reaches directly to our children."

While an element of choice or control for parents was seen with regard to the reading of books or magazines by their children, the fact that radio waves come into the house and that children may unwittingly (and unsupervised) tune into indecent broadcasts has long been used as an excuse for censorship. In Pacifica Foundation v. F.C.C., the famous Seven Dirty Words case, the Supreme Court referred to the "uniquely pervasive presence" of broadcasting (the case began when a man commuting home with his young son tuned into the broadcast, then complained to the FCC). The federal courts have given some hints as to the limits of the pervasiveness doctrine, pointing out that dial-a-porn services and cable broadcasting are not "pervasive" because, unlike radio waves, they are invited into the home.

The current Internet indecency law will be the first application of indecency regulation based exclusively on pervasiveness when there is no conceivable argument of scarcity.

Ithiel de Sola Pool said that pervasiveness is "a ticking time bomb.... This aberrant approach could be used to justify quite radical censorship."