I don't have overprotective parents (but they do protect me), simply because I've never given them a reason to be suspicious about anything. Just remember that it takes a while to build up a solid foundation of trust, especially when you reach the turbulent teenage years. That's not to say that my parents are never concerned about me or not wanting to know what I'm doing. My parents are involved in the right way...we have our sticky moments and sometimes I get on their case when things don't go my way because of them...but over these many years, I've learned to love it (because they're always fair and usually right) and I wouldn't have it any other way, ever.
Your parents are not spying on you. They're not being unreasonable. Take it from my view, an objective (outsider's) point of view. They love you. They want to be involved as best they can without being too invasive. Please trust me on this one. You may not see it in their eyes right now (sometimes even I don't with my parents) but someday you're going to thank them for being concerned. Someday you're going to be a parent yourself...right now you'll probably say, "I'll never put my children through this overprotectiveness," etc., but once you are a parent, you'll know exactly how they feel. Don't think of it as strictness, overprotectiveness, spying or anything. They're being parents and they care...very deeply, and they don't want to see their child fall...I don't know what it's like to see your own child fall yet...but I imagine that it hurts very much. I hope this helps and I'll be here if you want to talk more. Good luck with everything!