system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How does disney still own the rights to Mickey Mouse? Shouldn't it have expired a long time ago?
gpt
Steamboat Willie (1928) was subject to the 1909 Copyright Act granting protection for 56 years.  

With 1984 approaching, the Walt Disney Company (and others) lobbied Congress to alter the copyright act to be consistent with western Europe (author's life plus 50 years).  For corporations (which do not die) the copyright was extended to 75 years.

With 2003 approaching the Walt Disney Company again lobbied Congress to alter copyright law.  In 1998 the Sonny Bono Copyright Term Extension Act established copyright protection for author's life plus 70 years and 95 years for corporations.

Under current law, Mickey Mouse enters public domain in 2023.