Riff.cc is a private tracker torrent site that is completely focused on works distributed with creative commons, public domain, gpl or other free culture licenses.
It has some plans to allow tipping creators and seeders using digital currency.

You can use this invite to signup (I believe there is a limit of 90 people who can use it).

https://u.riff.cc/register/fb4dc3bf-af81-43f4-94fb-5afc6b24b159