Searching for “full title keys” online leads to:

We must distinguish between blatant piracy and community resources that operate in a gray area. A few resources exist, but understand their precarious status.

Title keys themselves are not the game data, but they are the door key to access copyrighted code. Courts have ruled that distributing encryption keys for copyrighted works is a violation of anti-circumvention laws.

: The CemuPiracy subreddit frequently features updated threads containing comprehensive "full" lists of keys for various regions.