Not a whole lot you can do to prevent individual acts like this:
SYDNEY — A gunmen took dozens of patrons hostage at a busy Sydney café on Monday morning, using some of the captives as human shields and forcing others to hold a black flag with white Arabic writing against the window.
The drama transfixed the normally calm Sydney, known for its laid-back vibe and relaxed population. By Monday night, five hostages had escaped and the Central Business District was virtually deserted.
The incident began during the morning rush hour, when a man with a gun entered the Lindt chocolate and coffee shop at Martin Place, a major transportation hub typically teeming with professionals and tourists. Authorities have declined to say how many hostages are inside, but no one has been injured, according to Police commissioner Andrew Scipione.
Authorities have been in contact with the gunman who has made a number of demands apparently including the right to speak to Prime Minister Tony Abbott. Local media have reported that he also requested an Islamic State flag. Earlier in the day hostages were seen with their hands up, pressed against the window while holding a flag that read: ”There is no God but God and Mohammed is the prophet of God.”