The Digital Millenium Copyright Act, or DMCA, was passed on October 12, 1998 to 
address piracy and copyright concerns specifically pertaining to software and 
Internet properties.  Brewster Kahle, from the non-profit company Internet 
Archive, petitioned the US Copyright office to grant copyright exemptions in the 
Digital Millenium Act to obsolete games.  To the delightful surprise of many, 
the Library of Congress approved the petition.  The exemption applies to games 
that require the original hardware as a condition of access, and if the game is 
"no longer manufactured or reasonably available in the commercial marketplace". 
This means that unsupported PC, console, and arcade games, are now legal to own.