Early adopters of the new iPhone 4S are raving about the new voice-activated Siri system that will make calls, set reminders, schedule appointments and send texts and emails. However, there is a serious security threat with Siri. The voice-activated feature will let anyone use the phone to send e-mails and text messages and make calls even if it is passcode locked, according to reports from Macworld.

Try it. Grab a friend's locked iPhone 4S, press the button and ask Siri to do something. You'll more than likely be able to send a text message, make a call and send an e-mail, all without knowing your friend's passcode. There have been many confirmed reports that Siri will allow access to addresses, phone numbers, and calendar events when the phone is allegedly locked and secure.  

While Siri poses a serious privacy and security threat, there is an easy fix for this situation. In the Passcode Lock settings, switch Siri to "Off." This enables authorized users to continue to use the feature once their iPhone is unlocked, but keeps unauthorized users from accessing these features when the phone is locked.  

Several Apple faithful are disappointed that Apple chose a default setting for Siri that put them at risk. While some users are frustrated that Apple was more concerned with impressing users than protecting them, the majority of iPhone 4S adopters are probably not even aware that they are at risk.

(To disable Siri so it can't be used unless the device is unlocked, you turn Siri "Off" in the Passcode Lock settings.)