Originally Posted by brockrwood

Actually, a copyright is hard to lose. In 1976 Congress changed the copyright laws. Works created after 1963 were allowed a generous extension period (this extension was made automatic in 1992). Later copyright laws have made even more extensions to the amount of time a copyright is valid. Works created from 1923 to 1963 had to be actively renewed when their first term expired to take advantage of the second, extended copyright period.

For all practical purposes, a vigilantly protected trademark can be renewed indefinitely. A copyright, on the other hand, will eventually expire, although the current laws provide for many years of protection.

- Brock