Is There a Copyright Law in Islam?

http://www.islam-online.net/fatwaapplication/english/display.asp?hFatwaID=79... Is there a copyright law in Islam? Some people say that knowledge is a common property and it cannot be restricted. They use the Hadith of the Prophet, peace and blessing be upon him, that "Wisdom is the lost property of a believer, it is his, wherever he may find it." What do you think of making copies of computer software?