Starting at midnight on January 1, tens of thousands of books (as well as movies, songs, and cartoons) entered the public domain, meaning that people can download, share, or repurpose these works for free and without retribution under US copyright law.
Per the Sonny Bono Copyright Term Extension Act of 1998, “corporate” creations (like Mickey Mouse) can be restricted under copyright law for 120 years. But per an amendment to the act, works published between 1923 and 1977 can enter the public domain 95 years after their creation. This means that this is the first year since 1998 that a large number of works have entered the public domain.
Basically, 2019 marks the first time a huge quantity of books published in 1923—including works by Virginia Woolf, Agatha Christie, and Robert Frost—have become legally downloadable since digital books became a thing. It’s a big deal—the Internet Archive had a party in San Francisco to celebrate. Next year, works from 1924 will enter the public domain, and so-on.
The last time the copyright law was changed to protect older works, it was because the copyright on Mickey Mouse was about to expire. Disney had a conniption, and got Mickey's copyright extended.
I wonder how long until they do that again. I doubt Mickey has entered the public domain. The howls from Disney would be heard nationwide.