They called her "Jezebel," a despised bible character who is depicted as a heartless, wanton woman - a temptress.
What she had worn was too provocative, they said – so the young men catcalled and hurled insults – and when she tried to defend herself, they attacked then stripped her.
The video footage, taken in a central Nairobi bus terminus last week, went viral. It is shocking to say the least, and quite difficult to watch without cringing. In the same week, another two women allegedly suffered the same humiliation.
The incidents have sparked outrage and an intense debate about how a woman - an African woman, should dress.
Yet the very act of undressing her is "unafrican" and indeed considered a taboo.
Two online campaigns are trending. "Mydressmychoice" is a pro-women's platform. Many of those contributing to the campaign say that they have a right to wear what they want, when they want, and that a woman is worthy of respect, regardless of what she is wearing or if she fits into society's model of what a woman should be.
Then there is the equally opinionated "Nudityisnotmychoice" campaign. Many [most being men] are saying that the debate should go beyond the incident and address the cause.
Those contributing argue that yes, women have the right to dress how they want, as long as it does not infringe on other people's rights.
Some argue that a woman should not go out in public with an outfit that is deemed "too provocative".
But the question has always been who determines decency, and who has the right to judge what someone decides to wear?
The debate is not limited to Kenya. Many African countries are conservative and blame Western influence on some of the cultures seen as "unafrican".
At the beginning of the year, female protesters took to the streets of Kampala in a campaign called "savetheminiskirt". They were protesting against a proposed law to criminalise short hemlines.
Namibian women responded to similar threats last year.
It won't be hard to find women with testimonies of harassment in many conservative countries in Africa, and even away from the continent.
Police in Kenya are investigating the latest incident and are under a lot of pressure to arrest the culprits. How they handle the case will be crucial in deterring other such acts.
If you speak to a lot of women in Nairobi, they will tell you that there are areas in the capital that they cannot go to when dressed in a certain way - areas where young, unruly men have given themselves the role of "fashion police".
Many women will tell you that at some point they have been harassed, humiliated and insulted because of the their choice of attire – very few report it to the police.
This is one argument that will not go away any time soon. Everyone has a right to their opinion. But no matter what the opinion is, they are all in agreement - there is nothing that justifies undressing anybody regardless of what they are wearing.