With the world's cheapest data, young Indians have lapped up Facebook, TikTok and WhatsApp. But when these toys are used as tools to organise protests or fuel unrest, the government gets scared. India is the world leader when it comes to cutting off access to the internet, activists say, despite the country's ambition to be a digital superpower.

Seven million Kashmiris have been offline since August, and over the past week mobile internet was cut for tens of millions of others during demonstrations against a new citizenship law criticised as anti-Muslim. Mumbai student Suvarna Salve said she and her friends started formulating tweets and eye-catching memes hours after the legislation was passed.

"We are using technology to amplify our message by means of tweets, posters, hashtags on Twitter, Facebook, Instagram, WhatsApp and even Telegram to mobilise people to come in large numbers to register their dissent," Salve told AFP.

"We are using social media with common hashtags to keep them on top of India trends," Salve said, adding that she was inspired by the youth-led pro-democracy movement in Hong Kong.

As of Thursday evening, the hashtags IndiaAgainstCAA and CAAProtest were among Twitter's top trends in India, with more than 300,000 tweets.

On photo-sharing app Instagram, posts offering advice on everything from what to take to a demonstration to what to do if you are detained by police have gone viral.

Politics has even made it to TikTok - which, like WhatsApp and Facebook, has more users in India than anywhere else and is usually a showcase for amateur Bollywood dance performances.

Now the Chinese-made platform is being used to share montages of marching students and videos - set to music - of police beating demonstrators.

Mohammed Javed, 23, initially heard about the demonstrations on social media. On Thursday afternoon, he made his way to a protest in Mumbai - his first.

"When I saw my friends sharing videos about this issue on TikTok and Instagram, I felt that I needed to be here," he told AFP.

There were no restrictions in Mumbai for Thursday's protests, which were peaceful, but elsewhere in areas where police and demonstrators clashed - and even where they didn't - mobile internet was blocked.

In India's northeast, where the current wave of anger began and where six people have died, a 10-day mobile internet blackout only ended on Friday.

On Thursday, people in parts of the national capital Delhi saw their phones go dead, unable to access the internet, make calls or send text messages.

And in Uttar Pradesh - home to over 200 million people - mobile internet and text messaging services were cut in several areas including in Ghaziabad, which neighbours Delhi.

There, like elsewhere, the demonstrations have not always been peaceful, with protesters hurling rocks at security forces and setting fire to buses and police outposts.

In Kashmir, where tens of thousands of people have died since 1989 in an anti-India uprising, most of them civilians, the government says that the blackout is to stop militants communicating.

But the shutdown has had a devastating effect on Kashmiris and the local economy, with the region's paltry dozen "internet kiosks" set up by the government being of little help, residents say.

Social media in India is also awash with misinformation with the government warning that at times of heightened tensions, the sharing of such material could "inflame passions".

This week New Delhi won praise from Chinese state media.

India's actions show "that shutting down the internet in a state of emergency should be standard practice for sovereign countries", an editorial in the People's Daily said.

"China's favourable statement effectively puts India in the same category as an authoritarian state," said digital rights activist Nikhil Pahwa.

"It makes it clear that democratic protest is being stifled in this country," Pahwa told AFP.

Prime Minister Narendra Modi's Bharatiya Janata Party and its supporters meanwhile have been avid users of social media to get their message across, as have their opponents.

"There has been an onslaught of tweets attacking our protests, so we are using social media to push back against them," student Salve said.

"If opposition IT cells can push forward their propaganda on social media, we are also countering that this time around instead of sitting on the margins."

But if an internet shutdown forces her and fellow protesters to log out, she said they would "use pamphlets and send volunteers across the city to create awareness".

"There's no stopping public protests now."