Replying to Is This Illegal?

I found out today that my boss was looking for my notebook at work. So he goes into my locker and looks inside there. The locker is the buisnesses property so i dont have any problem with him going through my locker. However i left my notebook in my zipper pocket on my pants. So the guy went into my pants pocket and took my notebook out.

Can I do anything about this? Me and him both hate eachother and tonight he's writing me up because i didnt fill the rest of my notes in for the night i was working. So if he fires me i want to know if theres something i can do about him going through my personal things...ie clothes