When my wife's phone was stolen last year, within 30 minutes I tried calling it and found it would go straight to voicemail. I immediately went to Find My iPhone and sent out a remote wipe order with a notification to be sent to me when it was accomplished. It wasn't until 7 or 8 days later that someone turned the phone on and it was wiped of all user data. Since that time, I have set up both of our phones to require an unlock code immediately and if the code is entered incorrectly 4 times progressively longer times are required between attempts. The 10th failed attempt will result in the phone wiping itself automatically. We were lucky that none of our personal data seems to have been compromised to date. Hindsight is 20-20 I guess.
Sent from my iPad3