|The voice-activated feature on the new iPhone 4S will let anyone use the phone to send e-mails and text messages and make calls even if it is passcode locked|
|Try it. Grab a friend's locked iPhone 4S, press the button and ask Siri to do something. I was able to send a text message, make a call and send an e-mail, all without knowing my friend's passcode. Another colleague confirmed that she could get an address and a phone number out of the phone and even see the calendar.|
There is a setting to not allow siri to be used while your phone is locked, but it is disabled by default. Some people may want to check their settings.