Yes. I always have a journal on my person to write stories, poems and thoughts in. When I was in high school, a girl whipped it off my desk and began reading it. I was mortified. She told me how great my stories was, but it didn’t help. It was the equivalent of peeking into my heart and poking around.
Aside from that, there was this messy business where a friend of mine logged onto my sister’s account and read her private messages in which she referred to him. I considered it a betrayal of her trust, my friendship, and didn’t speak to him for nearly a year (he approached me.)