Patents last 20 years only if you keep paying the maintenance fees. Edit: Here's and idea: The yearly fees for copyrights ought to be something like X = years

Patents last 20 years only if you keep paying the maintenance fees. Edit: Here's and idea: The yearly fees for copyrights ought to be something like X = years from publication, fee is X^X. So the first year would cost a dollar and the 10th year would cost 10 billion dollars. You can keep your copyright as long as you want!