Forget the image of a black-clad, AK-toting ISIS militant. If you're a woman living in ISIS-controlled Raqqa, Syria, they probably won't be the ones arresting you. The Khansaa Brigade is an all-female force tasked with enforcing ISIS laws. Mostly this means judging whether other women's abayas are loose enough or if they're being escorted by a male family member.
A woman unlucky enough to be deemed in violation of the rules by the Khansaa Brigade is arrested and taken into custody. The Khansaa Brigade station is independent of male facilities. The punishments range from fines to whippings, with the latter becoming more common. The punishments are carried out by women too, which is a marked change from how ISIS operates in other areas it controls.
ISIS generally has men enforce these rules, with Raqqa being the only known exception. At this point, it is still unclear whether or not the Khansaa Brigade is just a publicity stunt, or if ISIS is conducting an experiment in Raqqa to see if they want to implement it fully. If ISIS does decide to roll out the Khansaa Brigade throughout their territory, they certainly won't have a tough time finding female volunteers.
While the Khansaa Brigade dispenses unfair, violent punishment at the whims of its members, some women may view it as a sort of liberator. Brides of jihadists can expect to see their husbands infrequently at best, and since a woman isn't free to leave the house without a male escort, that means women are often locked away inside for days or weeks. ISIS banned the use of the Internet and television except for work-related purposes, so these women can't even escape to the digital world. The Khansaa Brigade offers these women a chance to leave the house and socialize, and to win a little bit of favor with their deranged occupiers.
The Khansaa Brigade is a kind of selling point for ISIS. Jihadists trying to recruit women online can use it to their advantage: women may balk at the thought living under of ISIS' deeply sexist and oppressive regime, but the Khansaa Brigade could be used as "proof" of gender equality. Women are the ones given the power to dispense justice and roam the streets free of an escort, and that may be enough to convince a radicalized woman who'd been on the fence.
While it's rarely mentioned in the news, the Khansaa Brigade is a terrifyingly powerful force: it offers a twisted kind of empowerment for women, and is a potent recruitment tool. That kind of influence can't be taken lightly.