Be it for promoting films, engaging with fans or speaking their mind about an issue, Bollywood stars use social media to their advantage. But since the virtual medium hardly has a filter, the celebs often invite unwanted attention from the troll brigade — or overzealous fans like in Salman Khan's case. Perturbed by abusive comments against his 'competitors' Shah Rukh Khan and Aamir Khan, he lashed out at his fans and threatened to quit Twitter.