Two minor points about Andrew Rindsberg's remarks on copyright.
 
First, while U.S. federal publications are usually not covered by copyright
protection (if authored by a government employee), those of state governments
(e.g., state public universities, state geological surveys) are protected by
US copyright.
 
Second, in the US, items published before 1923 (not "1909") are in the public
domain.  And many U.S. items published between 1923 and the late 1950s are
also in the public domain, if the copyright owner forgot to renew the
copyright registration on a timely basis.  (Renewal of copyright was required
at that time to maintain the copyright).  This exception does not apply to
foreign works.
 
Alan Kabat