Ask Joanne: What about Free-Range Eggs?(site info)
"'Free-range' is not a legal industry term; therefore it is essentially meaningless. Farmers use the term to imply that they practice a more humane standard of production but, in reality, there is no regulation regarding how the word is interpreted or used [in the US at least]."
http://vegsource.com/joanne/qa/qaeggs.htm