It’s a sad fact that the Internet isn’t always a nice place, which is why celebs like Lauren Bush Lauren, Leo DiCaprio and Christy Turlington -- plus our other Social Media Awards nominees Sophia Bush and Ian Somerhalder -- stand out from the roughly 550 million active Twitter users. These five celebs use their streams for good, mainly tweeting their support for everything from the environment to global maternal health, which is how they wound up nominated in our Best Do-Gooder on Twitter category. Learn more about these social good social media bees, and vote for your favorite before polls close this Sunday, September 15 at 11:59 p.m. ET. Be sure to tweet the celebs your support using hashtag #InStyleSMAs, and look for the winners to be announced in December on InStyle.com and in that month’s issue!