According to the news, which of the following social networking sites is NOT use

Presidential hopefuls in the United States still travel the country, meeting people and shaking hands. But now they also have to reach out for money and support online, and not just through official campaign Web sites. They also use social networking sites like Facebook and MySpace and video sharing sites like YouTube.
     Anyone with Internet access could record a question on video and send it in through YouTube. The debate aired live on CNN, the Cable News Network.
     Many of the questions involved foreign policy, especially the Iraq war. The mother of a soldier was concerned that her son is about to return to Iraq.