17 U.S.C. §110 includes exceptions to the exclusive rights of copyright holder for face-to-face teaching and for distance education.
The Digital Millennium Copyright Act (DCMA) 17 U.S.C. §1201 forbids circumvention of a technological measure that effectively controls access to a work protected under copyright.
Generally, it is a violation to go around any type of digital access controls if such access would be unauthorized.
There are limited exceptions for a few uses, including important educational uses.