I had a passcode on mine, plus had preview of texts off, and my ringer was silent with no vibration. I just texted my iPhone through MobileME with 2 mins of sound (despite all sounds and vibration settings off on my iPhone), and the screen alerted the person who had it with my name, apartment, contact number, and e-mail. That is how they were able to get it returned to me after I lost my iPhone.