Will thieves access my data on stolen iPhone?

[Kimmy]

I recently just had my iPhone stolen on the CTA. Two kids snuck up behind me and took it out of my hands. After chasing them, they got away, and the CTA worker told me "they're are too many stolen iPhone reports for police to care". To say I was extremely upset is an understatement.
I do not have Find my iPhone turned on. So i cannot erase data through there or iCloud
I do not have iCloud set up on my iPhone so they can't access photos or data through there.
I just logged out of my Facebook on my phone through my computer, and changed my password to EVERYTHING literally.
My phone has a 4 digit phone passcode.
After calling ATT my phone is now suspended.

I'm just terrified they will still be able to get in my phone and look at my information. I have information on my notes, emails linked (even though I changed my password, they could see my previous emails), and my pictures are all private. I feel my privacy is extremely violated.

What happens when a thief (two punk teenagers) steals an iPhone? How likely am I to have my phone searched?
Thanks

[Logan]

when a cell carrier receives a call that a phone ((iphone )) has been stolen they down the phone literally, when connected to a network it sends a signal and disables the phone and a message will show on the phones screen saying "this phone has been disabled" they will not be able to access anything.

my friend lost his phone and thought it was stolen as well and had is shut off, he eventually found the phone in the pocket of his jeans in his laundry basket and when he turned the phone on that message showed up on his screen and he wasnt able to do anything with it. had to have it wiped by his carrier and reactivated

[HoovR]

If it was that important then why didn't you have find my iphone on? There are all kinds of things you can do with that like track where it is, put permanent message on it, lock it, wipe it, etc. all from any browser.

[Rolly]

If you have changed all the relevant online accounts passwords, your account will be safe.
To prevent your new idevice from being stolen or lost in the future, I suggest you apply some free anti-theft apps like iLostFinder and set up Find My iPhone/iPad/iPod in iCloud on the device. It will take pics of the thief or finder when she/he tries to open your device with a wrong pass and then send the pics to your email etc. Hope it helps.
http://ikeymonitor.com/free-apps