mikhailxyohman
When the business/corporations no longer exist. Since the entity no longer exists there is no reason for a copyright.
But a corporation is immortal - even if it no longer exists under a specific name if it "dies" that just means it's bought out by a bigger one. I think any system that allows copyright to last _forever_ is fundamentally wrong.
Imagine if Shakespeare had formed a joint stock company or whatever that existed today and therefore his works would still be under copyright?!