IPhone :: Lost IP - Is My Data Safe?

I recently lost my iPhone.It was a first generation that I had managed to hold onto and keep working for years. I left it in the back of a cab and despite all my effort to relocate it, it appears it's gone for good.I had AT&T deactivate it 20 mins after I lost it. I also had the passcode feature active. AT&T has assured me that the combination of the two will pretty much render the phone a paper weight unless whoever found the phone restores it. I've never had to restore the phone, so one question I have is could whoever has my phone gain access to my data after restoring it? Like will iTunes back up the data for them and then allow them to download it again to the phone?Is my data safe? I work for a media organization and I had some very sensitive and valuable data on that phone. The kind of data I could lose my job over if a third party were to somehow access it. Not to mention the countless phone numbers and the huge log of text messages that contained sensitive personal information. Also, please spare me the ridicule of asking why I had so much important information on the phone.I've spent the last week beating myself up over it, and needless to say have learned my lesson. Trust me when I say I"ve punished myself enough over this.After an initial search, it appears there are illicit ways to hack the phone and get around the passcode, however my understanding of the subject is limited, and my question boils down to: can someone access the data on my phone?I"m merely looking for peace of mind here.