Lady Gaga has joined the vice-president of the United States Joe Biden in the White House 'It's On Us' campaign during a rally held at the University of Nevada in Las Vegas on Thursday. The 73 year-old politician praised and talked about Gaga's corageous act she made as announcing to the whole world that she was sexual abused when she was young. Biden also had the honor to introduce Gaga before her performance of 'Till It Happens To You' in front of many students saying: