If they restart my iphone can find my iphone can be activated

If your iPhone or iPad has been stolen and reset to factory settings you might not be able to activate Find my iPhone. However if it has just been turned off and back on you can.

If your iPhone or iPad has been stolen and you set up Find My iPhone, it cannot be reset to factory settings, as it is Activation Locked.

See: http://support.apple.com/kb/HT5818

You posted in the iPad forum instead of the iPhone forum. To get answers to your question, next time post in the proper forum. See https://discussions.apple.com/index.jspa I'll request that Apple relocate your post.

 Cheers, Tom 😉