One of the most disturbing aspects of the video, which has gone viral in France, is that people sitting in the cafe did very little except for standing up and looking shocked.
Laguerre keeps walking, but she eventually stopped to confront the man, turning to look at him.
"This is unacceptable behaviour", Laguerre wrote on her YouTube page.
Paris prosecutors have responded to the attack on Marie Laguerre by opening an inquiry into sexual harassment and armed violence, although the man has yet to be traced. Harassment is everyday. To those men who think anything goes in the street, who allow themselves to humiliate us and who cannot stand being offended, it is unacceptable. "I was really lucky that there was a video", she said.
That's when she said the harasser turned around and followed her down the street.
She told Le Parisien that she "got angry, and said, 'Shut up (ta gueule).′ I didn't think he'd hear, but he did", she added.
"He was able to send me noises / comments / whistles / dirty tongue, humiliating and provocative in my passage", she wrote on Facebook.
The man picks up an ashtray from a cafe table and throws it at Laguerre, who is now off camera.
Laguerre, however, took to social media to transform her experience into the latest illustration of the dangers that target women even in the most innocuous of public spaces.
But that was not the end of it as the CCTV footage from a nearby café shows, with the man walking towards the woman, pointing his arm at her in an aggressive manner. Regarding the attack on Laguerre, French Equalities Minister Marlène Schiappa said she was outraged, but not surprised. "I am sick of feeling unsafe waking in the street".
"Almost a quarter (22%) of young women in Sydney are harassed once a month or more, with more than 1 in 10 facing it on at least a weekly basis", said the report. It happens everyday. These men think they can do anything in the street, who think they are allowed to humiliate us and who don't like it when we are offended.
"I am very lucky to have been able to recover the video, it is a good tool for the fight of women", she said. This happens to us every day, women talk about it.
"I can not keep silent and we must not be silent".