Under U.S. copyright laws, facts cannot be copyrighted. Recent legal opinion has even decided that certain compilations of facts, such as telephone directories, are not subject to copyright.
But what about compiled genealogies? What can I include in a published genealogy without infringing on someone else's rights? And what rights do I have to the compilations I produce?
Stephen J. Danko has written a fascinating article that looks at some of the issues of genealogy facts and what can or cannot be copyrighted. Stephen doesn't supply all the answers but he certainly has some interesting observations. You might like to read his article at http://stephendanko.com/blog/2007/07/31/ethics-in-publishing-family-histories/.