This is why copyrights should need registration and renewal. They used to, and things dropped out of copyright when nobody paid for the renewal. There's a simi

This is why copyrights should need registration and renewal. They used to, and things dropped out of copyright when nobody paid for the renewal. There's a similar problem with mineral rights. US states register land ownership, but not mineral right ownership is not as well tracked. Litigation over abandoned mineral rights is not rare.