Pro-Hindutva activity on social media is widespread. Narendra Modi himself was quick to adopt social media to communicate with his supporters during the 2014 general election campaign, and continued to use it afterwards. The wider "online upheaval" by Sangh Parivar supporters, often involving hate speech and incitement to violence, played an important role in the election campaign.
The internet has allowed the production of Hindutva propaganda to be international, decentralised, and often to bypass legal restrictions on hate speech. Hindutva activity on social media is closely linked to the Hindu nationalist goal of creating a Hindu identity beyond caste, class and other divisions: according to one writer it aims to "forge new forms of Hindu identity, endow Hinduism with a purportedly more coherent and monotheistic form... create linkages across Hindu groups worldwide... and create something of global Hindu consciousness.
References: Links to articles on social media on Narendra Modi Facts; Rise of the Cyber Hindu, (India Today); Fascist Chatter, (deshi sense blog).