Trademark law is different from copyright law. With trademarks you do have to defend them: http://en.wikipedia.org/wiki/Trademark#Maintaining_trademark_rights

Trademark law is different from copyright law. With trademarks you do have to defend them: http://en.wikipedia.org/wiki/Trademark#Maintaining_trademark_rights http://en.wikipedia.org/wiki/Trademark#Maintaining_trademark... However with copyrights they are yours from the moment you write something down to 70 years after you are dead: http://en.wikipedia.org/wiki/Copyright#Obtaining_and_enforcing_copyright http://en.wikipedia.org/wiki/Copyright#Obtaining_and_enforci... (And the way things are going, that 70 year number will go up by 10 years every 10 years.)