Rihanna and Kim Kardashian, along with other celebrities, posted to Instagram and Twitter Tuesday to share the story of Cyntoia Brown with their followers. Brown, who is now 29 years old, was sent to jail in 2004 for killing 43 year-old Johnny Allen, who paid her for sex when she was 16. In her 2004 trial, Brown told the jury that he had taken her back to his house full of guns when she was a sex worker. Brown was sentenced to life in prison. The hashtag #FreeCyntoiaBrown was trending on Twitter Wednesday.