That's funny. I've had stories stolen for other websites for at least a decade. Oh, I've had books stolen as well. In the end, you realize that it's just the price you pay for being a writer.

On VK (the Russian Facebook), thousands of world famous authors have their work given away for free via ebooks.

If you write for Hubpages, they have software that tells you when your work is on other sites. Sites like Cloudflare (which I think Medium uses) protect these thieves from Google removing them from their search engines.