47 USC § 560
Scrambling of cable channels for nonsubscribers
through Pub. L. 116-344, except Pub. Ls. 116-260 and 116-283
(a) Subscriber request
Upon request by a cable service subscriber, a cable operator shall, without charge, fully scramble or otherwise fully block the audio and video programming of each channel carrying such programming so that one not a subscriber does not receive it.
(b) "Scramble" defined
As used in this section, the term "scramble" means to rearrange the content of the signal of the programming so that the programming cannot be viewed or heard in an understandable manner.