Excerpt from this article:
Milling on a vast field with his college buddies, Mr. Bhat, 18, cheered for Mr. Modi and his Hindu-oriented Bharatiya Janata Party, which was trying to wrest control of Karnataka state from the more secular Indian National Congress in legislative elections.
Yet the most intense political campaigning was not taking place on the streets. Instead, the action was happening on WhatsApp, a messaging service owned by Facebook that has about 250 million users in India.
Mr. Bhat, a B.J.P. youth leader, said he used WhatsApp to stay in constant touch with the 60 voters he was assigned to track for the party. He sent them critiques of the state government, dark warnings about Hindus being murdered by Muslims — including a debunked B.J.P. claim that 23 activists were killed by jihadists — and jokes ridiculing Congress leaders. His own WhatsApp stream was full of election updates, pro-B.J.P. videos, and false news stories, including a fake poll purportedly commissioned by the BBC that predicted a sweeping B.J.P. win.