According to this news report, a woman beat the crud out of a Saudi "tzniyus policeman" when he approached her and her male walking companion to ascertain if they were married or not.

When a Saudi religious policeman sauntered about an amusement park in the eastern Saudi Arabian city of Al-Mubarraz looking for unmarried couples illegally socializing, he probably wasn’t expecting much opposition.

But when he approached a young, 20-something couple meandering through the park together, he received an unprecedented whooping.

A member of the Commission for the Promotion of Virtue and Prevention of Vice, the Saudi religious police known locally as the Hai’a, asked the couple to confirm their identities and relationship to one another, as it is a crime in Saudi Arabia for unmarried men and women to mix.

For unknown reasons, the young man collapsed upon being questioned by the cop.

According to the Saudi daily Okaz, the woman then allegedly laid into the religious policeman, punching him repeatedly, and leaving him to be taken to the hospital with bruises across his body and face.
[...]
“The media and the Internet have given people a lot of power and the freedom to express their anger,” she said. “The Hai’a are like a militia, but now whenever they do something it’s all over the Internet. This gives them a horrible reputation and gives people power to react.”
[...]
"There is some sort of change taking place," Nadya Khalife, the Middle East women’s rights researcher for Human Rights Watch, told The Media Line. "There is clearly a shifting mentality regarding to the male guardianship law and similar issues. More women are speaking out, there are changes within the government, there is a mixed university, the king was photographed with women, they want to allow women to work in the courts and there are changes within the justice ministry. So you can witness some kind of change unfolding but it’s not quite clear what’s happening and it’s not something that’s going to happen overnight."

While I would not say the purpose of confronting self-appointed tzniyus police is in order to allow unmarried men and women to hang out together, I do believe in personal freedoms and if they choose to do so it is not the business of self-appointed (or any appointed) tzniyus police to stop them, let alone using the violent methods they have come to be famous for using.

And anyway it does not have to just be an issue with young unmarrieds. The tzniyus cops have been known to harass women whom they think are not dressed appropriately, married women sitting on "the wrong side of the bus", anybody who they suspect of doing something they consider wrong, as if they have a right to judge. Perhaps more women, and men, should have the courage to stand up to them the way the young woman in Saudi Arabia did and that might bring the end of the tzniyus police all that much closer...