I like the idea of an extension with a hefty tax. After an initial period of ~10 years, you have to declare the value of the IP each year and pay 10% of that p.

I like the idea of an extension with a hefty tax. After an initial period of ~10 years, you have to declare the value of the IP each year and pay 10% of that p.a. Anyone willing to provide your declared value to the public coffers can then have it placed in the public domain.