Because Mozilla takes a metric shitload of your data via fakespot such as (but not limited to)
Internet or other electronic network activity (e.g., browsing history, search history, information regarding an individual’s interaction with an internet website, application, or advertisement, and online viewing activities)
https://www.fakespot.com/privacy-policy
And then sells it to advertisers
No, actually its completely legal to consume content that was uploaded to the internet and then use it as inspiration to create your own works.