It's very difficult for individual authors to police where their work is being used.
I also wanted to respond about the cost that goes to the writer and what the writer is supposed to contribute. This is on the other topic you asked one of the panellists about.
When I did my first book back in 2001, the publisher did all the marketing and whatnot for the book. Now authors and writers are hired on the basis of their marketability—that is, their author's platform. They have to have thousands of followers on Twitter, Facebook, Instagram or whatever to get a publishing contract, because the publishers no longer provide the manpower to do the marketing.
We're getting less income, but we're also having to put in more effort. We don't just write the book anymore and let it go to the publisher; we have to do all that work along the way, and we get no additional compensation for it in most cases.