This is the link to Loujain Hathloul's twitter page. Hathloul is one of the women that was arrested for driving and held for two months in prison. She posts about a large array of topics but she is a female rights activist through social media in Saudi Arabia.
This article, from the Times, discusses the transition seen in Saudi Arabia after the death of Kind Abdullah. It specifically discusses the story of a woman, named Loujain Al Hathloul, who drove illegally and was stopped by police. The police took her passport and refused to let her drive. She took to Twitter about the experience as she sat for about a day in her car until she was arrested.