Yeah, baby! This is classic application for cryptocurrencies. It would even better if the original authors got the donations, so they at least get *something* from those pesky pirates. Imagine a decentralized iTunes.
As above posters have noted, BitTorrent Inc. is thrashing around this space with their BTT token and I haven't tried it but it's probably junk.
Problem: Scanning the whole blockchain for a magnet hash is inefficient. Furthermore, there's no guarantee that the Bitcoin address attached to it is the same as the torrent creator.
Solution: The Bitcoin donation address can simply be encoded in the torrent metadata itself, which is hashed into the magnet link by the torrent creator, thus ensuring that they are the ones who inserted the address. I propose simply adding a zero-length file to the torrent with the name "<currency code>:<address>".
{
"announce": "http://tracker.site1.com/announce",
"info": {
"files": [
{"length": 111, "path": ["111.txt"]},
{"length": 222, "path": ["222.txt"]}
],
"name": "my-music",
"piece length": 262144,
"pieces": <binary SHA1 hashes>
},
"donations": {
"xbt": <bitcoin address>,
"xmr": <monero address>
}
}
Whaddya know!? Frostwire and qBittorrent already do this!
https://blog.frostwire.com/2014/02/27/frostwire-integrates-bitcoin-donations-and-creative-commons-licensing-into-torrent-files/There's also the weakness that the torrent is only hashed with SHA-1, but that's another discussion.
References:
https://www.bittorrent.com/token/btt/https://en.wikipedia.org/wiki/Torrent_file