Jenna Miscavige Hill grew up in Scientology. She left in 2005 and became an outspoken critic of the group. Along with two other former child Scientologists she created a website : exscientologykids.com. Recently she released a book, Beyond Belief: My Secret Life Inside Scientology and My Harrowing Escape.
Speaking out the way Jenna has puts her in a dangerous position as a suppressive person (SP) with the Scientologists. It makes her "fair game" in the eyes of the group which means that a person is judged a threat to Scientology and they can be punished and harassed using ANY and ALL means possible.
You can read more about the "Fair Game" policy on www.wikipedia.org.