Since Barack Obama took the presidential office, the rate of threats against the US president has increased 400 % from the 3,000 a year or so under President George W. Bush, according to Ronald Kessler, author of In the President’s Secret Service.
Some threats to Mr Obama, whose Secret Service codename is Renegade, have been publicised, including an alleged plot by white supremacists in Tennessee late last year to rob a gun store, shoot 88 black people, decapitate another 14 and then assassinate the first black president in American history.
Most however, are kept under wraps because the Secret Service fears that revealing details of them would only increase the number of copycat attempts. Although most threats are not credible, each one has to be investigated very carefully.
According to the book, intelligence officials received information that people associated with the Somalia-based Islamist group al-Shabaab might try to disrupt Mr Obama’s inauguration in January, when the Secret Service co-ordinated at least 40,000 agents and officers from some 94 police, military and security agencies.
More than a dozen counter-sniper teams were stationed along the inauguration parade path and the criminal records of employees and hotel guests in nearby buildings were monitored.