1. Over exposure? As you've read, parents are almost always out to protect their babies. If you haven't already I suggest you ask them the "why" question.
2. There has been a lot of suicides linked to cyber bullying. Also, there are simply a lot of bad people on the web who would love to know where you lived/what school you go to/etc. Parents often forget what it is like to be a teenager. They don't understand how we (as kids/young teens/young adults) think and process information. Therefore their reactions often seem off and unreasonable to us. Let them know what you are capable of.
3. Similar to #2. The thing is, though, untrustworthy parents often raise defiant kids. I'm not one to say that their parenting is terrible, simply that the style is often misleading.
4. Do they know your dreams? Do YOU know your dreams? What you want now isn't always something you will in certain do in the future. Parents know this well through past experience. That in mind, I can also say that experience comes from failure. If you don't succeed- stick with it. That is how we reach our ultimate goals. If your target is reasonably reachable (say an inspiring dancer and not an underwear model) you should be able to talk to your parents about it. They should be able to listen to you respectively and help you achieve your greatest goals.
5.Show some responsibility- street smarts. Go out with a reasonably large group of friends one day, than decrease the numbers to a respectable level where your parents don't have to worry for your safety. With time.
6. When I go to school (or work/sports events/whatever) I usually am happy and care-free. But on school days when I come home I am often grumpy and annoyingly nonchalant. My dad often doesn't understand me either these days. Teen hormones I guess. But on weekends I am myself again. This allows my parent to see I'm not always a spoiled sour demon-child.
Good luck. It's ultimately up to you and your ability to smooze. Never lie to your parents and respect their decisions, and they should be able to do the same. Some day you'll see their not so unpredictable after all.
No matter where you go, there you are.
--->WORDS FROM THE HORSE'S MOUTH