There are exceptions, but usually when parents snoop it's because they have a fear--warranted or not--that their kids are doing something that's going to be bad for them. It's hard for them to trust that their kids will share difficult decisions at this age, when young people are really beginning to carve out their individuality.

Some of this, of course, is true. Privacy is important, especially when you're a teen. Young people are finding their way at this age and want to figure some things out for themselves. Not many teens want their parents all over everything they do.

If you have been doing things like breaking curfew or hanging out with a different crowd of friends--behavior that is different or unusual for you--then she's probably trying to explain that behavior. But even if you haven't done anything usual, I would recommend talking to your mom and telling her how much this bothers you. Ask her what she wants to know and tell her that you would rather have her communicate her concerns directly rather than looking through your things. Then try to talk to her as honestly as you can about what she has questions about. End the conversation by letting her know that she can come and ask you directly any time she has a concern or question about something.

It would probably be better to have this conversation at a time when you are not upset. Having a screaming match might just make her wonder what you're being defensive about.

You might also try sitting down and talking to her about what's going on in your life more often. Letting her in a little may help her feel that she DOES know what's going on and it may help bring the trust back into the relationship.

Good luck.