I really hate when my kids take my things without asking
I feel you!  My two kids know all the rules and yet, they just go out the window when they want to take something or use something that isn't theirs.  I always joke that you can't have nice things with kids.
It's true tho. They will one day understand when the spend their own money on things and someone just comes along and breaks it or leaves at the mall.
Seriously!
I hope tht time comes sooner thatn later