I'm trying to remember the title of a book I've read a few years back. It was about a young woman serving in the military on Earth, who saw something she shouldn't have and had to flee to another planet where other exiled people had created a sort of liberal socialistic society. After a few months (years?) officials on Earth discovered where the woman has been all this time and a war breaks out. I can't really remember the end though.
Oh, and I think every person on Earth is implanted with a sort of tracking device/chip that monitors all their activities. The cover had some spaceships fighting in the back, and a blond woman holding a gun and running in the foreground.