This is copied from a news paper artical. Seems like this could potentially be pritty serious. Artical can be found here Two security experts say they have discovered a major flaw in the Apple iPhone that would let hackers take control of the device with text messages - and they plan to reveal the technique to the world at a security conference today. iPhone users are being warned that once the method is revealed they should be wary of potential attacks. Researchers say the 'hack' could rapidly spread from iPhone to iPhone and cause chaos. If they receive a text message with a single square character, they are advised to turn the phone off immediately. 'This is serious,' one of the researchers, Charlie Miller, told Forbes. 'The only thing you can do to prevent it is turn off your phone. Someone could pretty quickly take over every iPhone in the world with this.' Miller and his colleague Collin Mulliner plan to reveal details of the attack later today at the Black Hat security conference in Las Vegas. They say the attack works by sending a burst of SMS messages to the iPhone, which allows them to hijack the phone and take control of its functions - including sending texts to hijack other phones from the user's contacts list. The only warning a user would get that this was happening, they say, would be a single text message with a lone square character in it. Miller and Mulliner say they contacted Apple to warn them of the vulnerability over a month ago, but that Apple has yet to fix the flaw. Apple has not yet commented on the alleged vulnerability; the company tends not to discuss software problems until it has released a fix. Miller and Mulliner also claim to have discovered other SMS-based attacks that can be used to take control of Windows Mobile devices, and another text attack that lets them knock iPhones and Google Android phones off their wireless network. Google says it has patched the security flaw in Android since being informed of it.