John R. Gammino [INV] filed suit against AT&T, CenturyLink, Nextel, Sprint, Sprint Nextel, Verizon, Virgin Mobile, and unknown subsidiaries, alleging that the defendants’ prepaid calling services infringe a patent related to placing prepaid telephone calls through a central office from a mobile device.  Gammino asserted the patent-in-suit against the same defendants in December 2011 and May 2010, but the cases were dismissed without prejudice.  Gammino has reasserted the same patent in the present suit.  He has filed suit 10 prior times since October 2003 against more than 20 defendants and was subject to one action for declaratory judgment filed by Nextel, Sprint, Sprint Nextel, and Virgin Mobile in November 2011.  5/29, District of Delaware, no judge yet assigned, 1:2012cv00666.