Arguably the most emotional moment of the Oscars, Lady Gaga's passionate performance of "Til It Happens to You." Introduced by Vice President Joe Biden, Lady Gaga has turned out some powerful performances recently, but she saved her best for the Oscars. The Oscar-nominated "Til It Happens to You" was written for The Hunting Ground, a documentary about sexual assault on college campuses. Gaga has been actively and passionately involved in raising awareness for the issue, and has been open about how she, too, is a survivor of rape. She was able to channel her anger, frustration and passion into one hell of a performance with a grand finale that featured a whole group of sexual assault survivors, standing together in solidarity. The song brought the Oscar audience to its feet and a few to tears. Check out the performance above!