Yet the O'Donnell campaign has not done so. Why?
You tell me. You seem to know all the answers.
Easy. It keeps the kettle from boiling over. No doubt O’Donnell regrets ever mentioning being followed, but that’s an opening for Castle’s people to keep the issue front and center. So she steps into a trap if she goes ahead and prosecutes the privacy invader. Therefore, she wisely decides to let it go quietly, especially if she thinks there is no particular threat to her person, just an irritating invasion of privacy. She reduces her exposure on an issue that doesn’t help her. That’s a good thing.