I don’t think that understanding is correct. Content in the public domain is not “protected under this title [copyright law]” https://www.law.cornell.edu/uscod

I don’t think that understanding is correct. Content in the public domain is not “protected under this title [copyright law]” https://www.law.cornell.edu/uscode/text/17/1201 https://www.law.cornell.edu/uscode/text/17/1201 > (A) No person shall circumvent a technological measure that effectively controls access to a work protected under this title