Paola, who asked that her last name be withheld for privacy and safety reasons, said she was motivated to create private online forums to help facilitate this type of information-sharing about dating experiences among women. Some of these groups count thousands or tens of thousands of women as members. Due to the nature of dating apps, she said, people "can easily get away with ... hurting girls, cheating, lying and all that stuff."

"It's very needed, something to prevent that," she said. But as more and more women join her groups, some men have learned they've been the subjects of some of their posts. . Then come takedown requests and legal threats, directed at both members and the groups themselves.