They seek to force silent authorities and a reticent society to confront "sexual terrorism".
The victims of the attacks started talking openly about their ordeals, insisting they would not be intimidated by a campaign they believed was aimed at shunning them from public life.
"We are not victims, we are revolutionaries. What happened to us has made us stronger and we will continue" to take to the streets, said activist Aida al-Kashef.
Harassment of women is by no means new on Egypt's streets, where they were often the target of verbal abuse and sometimes groping.
But since the revolution that toppled long-time president Hosni Mubarak in 2011, the problem has snowballed, with women now being regularly attacked by mobs of men in and around Tahrir Square.
The attackers have stripped women of their clothes with knives, sexually assaulted them and penetrated them with their fingers.
Yasmine al-Baramawy, who was assaulted in November, highlighted the degree of violence when during a talk show she held up the ripped trousers she wore the day she was attacked.
"They gathered around me and started ripping my clothes off with knives," said Baramawy.
She was then dragged several hundred metres, while being touched and groped, until residents of a neighbouring area saved her from the crowd.
"I didn't feel sad or feel that my pride had been damaged. I felt angry and I want justice," Baramawy said.
Outraged Egypt citizens came together to form groups such as Operation Anti Sexual Harassment and Tahrir Bodyguard that brought together volunteers to intervene to stop the attacks in Tahrir Square where police were largely absent.
The groups also offer medical and psychological support to the victims.
On January 25, as thousands of Egypt's people marked the second anniversary of their uprising, at least 19 women were assaulted, according to Operation Anti Sexual Harassment.
Some argued the attacks were politically motivated.
"These attacks aim to exclude women from public life and punish them for participating in political activism and demonstrations. They are also an attempt to ruin the image of Tahrir Square and demonstrators in general," said the group.
"This phenomenon requires urgent attention and treatment, and is linked to the broader social problem of endemic and daily sexual harassment and assault of women," it said.
"We do not want to use the term 'harassment.' What is happening today is sexual terrorism," said Inas Mekkawy, a women's rights activist with the group Baheya.
Indifference and scorn
A large part of the problem lay in the indifference of the authorities and society's scorn.
"They ask the victim: 'What were you doing in Tahrir? How were you dressed? What time did you go?" Soraya Bahgat of Tahrir Bodyguard said.
Another member of the group, Ahmed Shokri, who intervened in "six or seven" of such attacks, recounted one of the incidents.
"Some people had belts in their hand, others had knives. You don't know who is doing what. We try to form a cordon around the women and try to pull them [to safety] into the entrance of a building or a shop," he said.
"The problem is that there are people who say they are coming to help, but we don't know if it's true … That day, five men told me: 'I'm the brother of the girl.' I believed the first one, but then there was a second then a third then a fourth. I understood then that these people know what they're doing," Shokri said.
To the fury of many activists, members of Egypt's upper house – the Islamist-dominated Shura Council –recently heaped blame on the victims because they "know they are going somewhere where there are thugs", according to local press reports.
One senator even called for the segregation of men and women during demonstrations, while another said the tents used for the sit-ins in Tahrir Square became a place of prostitution.
Abu Islam, a controversial Islamic preacher and satellite television channel owner described the women as "naked, non-veiled", and said they went to Tahrir "to get raped". The National Council for Women said it was tasked by the prime minister with drafting a comprehensive law against all forms of violence against women.
But activists said they were sceptical about the impact of such a law in the absence of a real will to apply it. – AFP