NFT marketplace halts transactions due to 'rampant' counterfeiting

I've been browsing for some tile art for a hobby project. OpenGameArt.org is a great resource with a variety of liberally licensed works by some great artists. They now have a big banner up on the site, presumably due to need:

> WARNING: Taking art from OpenGameArt.org to be sold as NFTs? You may be committing FRAUD.

https://opengameart.org/content/warning-taking-art-from-open...

https://opengameart.org/content/note-of-caution-to-nft-purch...