This is from an article on Mickey Mouse that was linked to in the original Sherlock Holmes article:
Here is where it gets tricky: Disney also holds trademarks on its characters, including the “Steamboat Willie” version of Mickey Mouse, and trademarks never expire as long as companies keep submitting the proper paperwork. A copyright covers a specific creation (unauthorized copying), but trademarks are designed to protect against consumer confusion — to provide consumers assurance about the source and quality of a creation.
Boiled down, any public domain use of the original Mickey cannot be perceived as coming from Disney, Ms. Ginsburg explained.
Source: https://web.archive.org/web/20221227170631/https://www.nytim...