Automated Twitter “bot” accounts made a massive attempt to boost traffic on the platform in India in February, as the countdown to the world’s largest general election began.

The accounts were deployed on a massive scale on February 9-10 and boosted hashtags both in support of and in opposition to incumbent Prime Minster Narendra Modi, with small groups of accounts pushing out thousands of posts an hour. The accounts were domestic in origin and substance.

The incident highlights the sheer scale of attempts to manipulate Twitter traffic as India’s main political parties head to the polls. It also underlines the extent to which social media more broadly has become an electoral battleground.

India’s 875 million voters will be heading to the polls between April 11 and May 18. The ruling Bharatiya Janata Party (BJP), led by Modi and party president Amit Shah, while still the favorite, has recently slipped in the polls. The major political parties have launched large-scale electoral campaigns with a significantly larger focus on digital strategy, compared to the previous election in 2014.

While bots were used on both sides on February 9–10, the pro-Modi traffic was far more heavily manipulated than the anti-Modi traffic and, indeed, far more heavily manipulated than any large-scale traffic flow the DFRLab has analyzed as of yet. Conversely, while the scale of the activity was vast, its impact was rather muted given the relatively low number of followers of the accounts. The massive scale of the attempted manipulation nevertheless bodes ill for the quality of online debate in India as the election approaches.

Twitter’s systems are designed to detect large-scale automated efforts like this without necessarily suspending the accounts straight away: the bot traffic is therefore remarkable for the sheer effort it represents, rather than for its impact.

It remains important to be able to expose such efforts. The appendix to this article sets out one method for doing so, for the benefit of the open-source community, and identifies the record-breaking rate at which the accounts were posting.

#TNwelcomesModi

The DFRLab scanned traffic on the hashtag #TNwelcomesModi, short for “Tamil Nadu welcomes Modi,” which trended in India on February 9–10 and was mentioned over 777,000 times in two days. The hashtag referenced Modi’s visit to the southern state, where the BJP is historically weak.