Image copyright Juliana de Faria Image caption Juliana de Faria started the hashtag "primeiroassedio" after a 12-year-old girl on Masterchef became the object of crude sexual comments online

How old are young girls when they are "first harassed" by men?

Women in Brazil are reflecting on their own childhood experiences - and sharing these stories on the internet in big numbers. It began with a sordid episode on Twitter as the nation watched the junior version of Masterchef, the globally popular TV cooking competition.

One of the contestants on the programme was 12-year-old Valentina Shulz and during one episode, several men started tweeting suggestive messages about her online using the show's hashtag. "Does anyone know the Twitter of Valentina? She will date me if she wants it or not," wrote one user. "If she wants it, it's not paedophilia, IT'S LOVE," said another.

These disturbing messages were noticed by Juliana de Faria, a journalist and part of the feminist group Think Olga. She started tweeting about the times she was harassed as a minor. Soon, others shared their stories too and Faria started a hashtag - "primeiroassedio" - which translates as "first harassment".

"Suddenly some readers and followers of Think Olga were writing me back with the first time they were harassed and they were very, very young, as young as five years old. So I started retweeting that," Faria told BBC Trending radio.

The tag has been used more than 90,000 times, with women and girls sharing the stories of their first encounter with public sexual harassment. "At 11, I was heading to my dance class and a man touched my bottom," tweeted one. "13 years old. I was going to the supermarket. Heard from a gentleman that I already had 'beautiful boobs.' #firstharassment," said another.

Listen to BBC Trending Radio

Hear more on this story - and more from the Trending team - on BBC World Service radio. Or download our podcast.

BBC Trending radio spoke to one woman who shared a longer account of an even more harrowing ordeal. Luisa Guimaraes wrote a Facebook post recounting how she was raped by a taxi driver in Rio de Janeiro, when she was 21 years old.

She wrote about how she began to experience harassment by men from a very young age. "Like all women I have - hair pulled back, body straightened - walked with extreme fear when by myself. I have suffered verbal harassment," she wrote. "I've been chased down the street... for answering a workman who wanted to - in his words - 'eat all of you.' On the street, on the bus, partying, in college, day and night, aged 12 and 22."

She remembers first being harassed when she was nine or 10 and said that after that it happened nearly every day on the street.

"It can happen when you're walking down the street and someone is catcalling all the time, or you're going to a party and some guy wants to talk to you or kiss you and you don't want him to... and he gets aggressive and starts calling you names," she told Trending.

"That has happened a lot to me and to a lot of my friends. We live this every day."

Reporting by Luis Barrucho, BBC Brasil

Blog by Olivia Crellin

Next story: The Kenyans who attacked Robert Mugabe on Twitter

Fake Mugabe comment starts a Twitter War between Kenyans and Zimbabweans. READ HERE

You can follow BBC Trending on Twitter @BBCtrending, and find us on Facebook. All our stories are at bbc.com/trending.