How about different lengths for personal and corporate copyrights?

[jj_frap]

Personal copyrights: Life of owner.

Corporate copyright: To account for the fact that a corporation is a person that can theoretically live forever, how about 14 years? That was the length of all copyrights in the U.S. from the 1770s to the 1920s, and people still created things back then. :-P

[pvn]

Why not limit all copyrights to 14 years then? Why not 15? Or 20? or 200?

Why should personal copyrights be limited to a certain person's lifetime? My land doesn't become public property when I die, why should my intellectual "property"?