It was 3pm on a Saturday afternoon. Diya Pinto was dozing under a tree in Bangalore's Cubbon Park. A few feet away, Lijya Perayil was wide awake. She usually found it impossible to close her eyes on these mid-day visits to the park that she and her friends made every Saturday.

A security guard walked briskly towards them, blowing on his whistle. Most of Perayil's 14 friends sprawled around the tree kept on sleeping. But Perayil and her friend Satya Gummuluri sat up. "You cannot sleep here," the guard told them. "This is a public park. Anyone can sleep here," said Gummuluri, pointing out the man sleeping nearby. "It is not safe for you," the guard clarified. "Why are you not waking up that man," asked Perayil. "Oh that man comes here every day," said the guard. "He says his prayers and goes to sleep." "Well, don't worry about us. We're only sleeping, too," Gummuluri retorted.

Yet the young women were not desultorily sleeping in a park. They were members of Blank Noise, a volunteer-led collective committed to tackling attitudes on sexual violence. One of its projects is Meet to Sleep, where women of all age groups come together to sleep in public places.

Started in 2003 by Jasmeen Patheja as part of her graduation project at the Bangalore-based Srishti School of Art Design and Technology, Blank Noise mobilises citizen "action heroes" through its projects, events and campaigns and has been instrumental in shaping the discourse on street harassment in India. "Back then 'street sexual violence' was dismissed as mere 'eve-teasing', challenging us to break the culture of denial and silence around individual experiences," says Patheja.

Blank Noise is but one of six or more active web-based outfits that have sprung up in metropolitan cities to make cities safer for women, most of them after the Delhi rape case in 2012. These don't confine their activities to the Internet - they also promote activities on the ground such as walking in groups at night in relatively unsafe places.

Says Calcutta-based social activist Aloka Mitra, who has worked for decades with rescued trafficked girls, "Cyberspace has increasingly become a power platform for rallying public opinion and action. But it needs to be coupled with action on the ground to prevent it from becoming a well-informed group just talking among itself".

Why Loiter, an online group formed by Shilpa Phadke, author of a book titled just that, sends groups of young female volunteers to hang about or "loiter" around unsafe places - its way of reclaiming public space where women do not feel welcome. The co-ordination is done online.

Safecity, started by Elsa Marie D'Silva and two of her friends in December 2012, keeps track of where people have faced sexual harassment. It puts up location-based maps mentioning the number of cases in an area and teaches women to be proactive and lobby with the police. It uses the complaints lodged by the public on its site to create these maps. Safecity has garnered over two lakh hits and has around 50,000 likes on its Facebook page. "We plan to collect one lakh reports over the next year or so concentrated in Mumbai, Delhi, Pune, Goa and Bangalore. Our mobile app should be out by June," D'Silva adds.

Safetipin is an app that can be downloaded for free. Kalpana Viswanath and her team collate data through crowd sourcing and audit how safe (dangerous, less safe, or safe) a spot in cities like Delhi, Pune and Bangalore is. First offered in November 2013, the app has been downloaded 35,000 times. "The online movement is a powerful tool and should be coupled with on-ground activity to make it effective. It is really catching on since it gives scope to talk and exchange ideas," feels Viswanath, who also heads Jagori, a non-government organisation for empowering women.

Calcutta too has its share of online movements. Madhura Chakraborty, a 29-year-old researcher, decided to deal with the safety issue by forming Take Back The Night (TBTN) along with a friend a little after the Delhi rape case. TBTN organises events such as Walking the City at Night (groups of people walk down a road late at night, painting artwork on the pavements and slogans on the walls to spread awareness); Game Nights (usually under the Gariahat flyover where men have been playing carroms for ages); monthly gatherings in unsafe areas and taking public transport in large groups late at night.

"It's not just that women are being attacked in public spaces; their entitlement to urban spaces is also being questioned. During nights, women have to always justify their presence on the roads," says Chakarborty.

Way back in 2006, Blank Noise held a "Blogathon", where bloggers shared their experience of street harassment. This led to hundreds of bloggers building testimonies of street harassment and forming chapters in cities including Chandigarh, Chennai, Delhi, Hyderabad, Jaipur, Calcutta, Lucknow, Mumbai and Pune.

The group's volunteers have also conducted a campaign, Being Idle, where they occupy city railings and make eye contact, and Hahaha Sangha which brings together a diverse group of women to laugh out loud in their neighbourhood park.

All these groups use social media to mobilise people and change attitudes. "We use web platforms, including Twitter and Facebook, and mobile technology for co-ordination across multiple location and cities. The interventions are designed to break the fear-based relationship women have with their cities," explains Patheja.

Still, using the social media has its flip side too. "You can never be sure of the exact number of people who will participate. You may get a thousand responses, but only a few might actually turn up. Also, the reach is limited to English-speaking Calcuttans who have access to the Internet," admits Chakraborty.

Inspired by Blank Noise, Chakraborty plans to strike conversations with strangers in "unsafe" places in the city to dispel fear. She is also thinking of installing thought-provoking artwork in rickshaws and tea stalls and holding public film screenings showcasing the city during nights.

"Web-based organising enables immediacy, spontaneity. Different protests are designed for different needs and concerns. Some come in a wave and make an impact within that time span. They trigger a dialogue. Blank Noise is committed to building long-term dialogues and collective ownership of sexual violence," says Patheja.

Clearly, in a society that sees incidents of sexual violence on women every day, the efforts of Patheja and others of her ilk will add to the movement to change the tide in favour of women.