What if the person that steals it jail breaks it

Possibly, but that assumes they can get into it in order to jailbreak it. If it was stolen then it's gone. Why worry? Set Find My Phone to erase it when it goes online if you want to prevent access to any content.

What To Do If Your iDevice or Computer Is Lost Or Stolen

iPhone, iPod Touch, and iPad

If you activated Find My Phone before it was lost or stolen, you can track it only if Wi-Fi is enabled on the device. What you cannot do is track your device using a serial number or other identifying number. You cannot expect Apple or anyone else to find your device for you. You cannot recover your loss unless you insure your device for such loss. It is not covered by your warranty.

If your iPhone, iPod, iPod Touch, or iPad is lost or stolen what do you do? There are things you should have done in advance - before you lost it or it was stolen - and some things to do after the fact. Here are some suggestions:

1. Reporting a lost or stolen Apple product

2. Find my lost iPod Touch

3. AT&T. Sprint, and Verizon can block stolen phones/tablets

4. What-To-Do-When-Iphone-Is-Stolen

5. What to do if your iOS device is lost or stolen

6. 6 Ways to Track and Recover Your Lost/Stolen iPhone

7. Find My iPhone

8. Report Stolen iPad | Stolen Lost Found Online

It pays to be proactive by following the advice on using Find My Phone before you lose your device:

1. Find My iPhone

2. Setup your iDevice oniCloud

3. OS X Lion/Mountain Lion- About Find My Mac

4. How To Set Up Free Find Your iPhone (Even on UnsupportedDevices)

Mac Computer

Find My Mac can be used from Find My Phone at iCloud.com and via Find

My Phone on your iDevice.

The following is third-party anti-theft software:

1. STEM 2.1

2. MacPhoneHome 3.5

3. MacTrack 7.5.0

4. VUWER 1.7

5. Sneaky Bastar* 0.2.0

6. Undercover 5.1.1

7. LoJack for Laptops

8. Hidden 2.0

It might. Jailbreak is a forbidden duscussion subject in this forum so no one who knows can say. But unless you can get it back (which seems unlikely) it is the concern of the thief.