For free real time breaking news alerts sent straight to your inbox sign up to our breaking news emails Sign up to our free breaking news emails Sign up to our free breaking news emails Email * SIGN UP I would like to be emailed about offers, events and updates from The Independent. Read our Privacy noticeThe U.S. Secret Service has found and is quietly dismantling a massive network of “SIM farms” across the New York area just as world leaders gather for meetings at the United Nations. McCool compared the potential impact to the cellular blackouts that followed the Sept. 11 attacks and the Boston Marathon bombing, when networks collapsed under strain. So what are these SIM farms and what are they capable of? What the tech doesSIM farms are hardware devices that can hold numerous SIM cards from different mobile operators.