... without my permission?
Yes. When you are on school property, you basically agree to any rules on the property. Which is hard when you're in Jr. High or High School. Now if they share the private information with the rest of the class that's a little bit of a different story. It also depends if you are in public school or any variation of private school. College is a different story. The same thing can apply, but to an extent.
Your teacher is allowed to do whatever she wants in HER classroom. It doesn't matter if it was personal, you are in her classroom, you're wasting her time, passing notes.
You are in school to learn, not chat. Do that on your own time, not time that your parents pay to have you educated. Your teachers have worked hard to become a teacher, don't waste their time.