17 USC § 1201
(2) No person shall manufacture, import, offer to the public, provide, or otherwise traffic in any technology, product, service, device, component, or part thereof, thatâ
(A) is primarily designed or produced for the purpose of circumventing a technological measure that effectively controls access to a work protected under this title;
(B) has only limited commercially significant purpose or use other than to circumvent a technological measure that effectively controls access to a work protected under this title; or
(C) is marketed by that person or another acting in concert with that person with that personâs knowledge for use in circumventing a technological measure that effectively controls access to a work protected under this title.
[...]
(2) As used in this subsectionâ
(A) to âcircumvent protection afforded by a technological measureâ means avoiding, bypassing, removing, deactivating, or otherwise impairing a technological measure; and
(B) a technological measure âeffectively protects a right of a copyright owner under this titleâ if the measure, in the ordinary course of its operation, prevents, restricts, or otherwise limits the exercise of a right of a copyright owner under this title.