An anonymous reader writes: When President George W Bush attends the APEC Summit in Sydney, Australia in September, his motorcade will be shadowed by a helicopter equipped with signal-jamming equipment, blocking cell phone reception around it in an area the size of a football field. However, government officials plan to allow emergency calls through but a telecommunications researcher says this isn't possible. "We're not convinced you'd be able to do that. There's no distinction between outgoing emergency and normal calls," said Jeff Kasparian of the Institute for Telecommunications Research in Australia. Terrorists have used mobile phones to detonate remote-controlled bombs in Iraq and in the recent Bali bomb attacks.