Huang Jieli, who ran a Chinese ride-sharing business called Hitch, was invited to a wedding in March. One of her drivers was getting married to a woman who had once been his passenger. Thanks, the invitation said, for getting them hitched.

Didi Chuxing, Hitch’s corporate parent and one of the world’s most successful and valuable start-ups, once cheered these stories of young love. Like so many other Chinese internet companies, Didi explored all kinds of ways to bring in new users, including social networking.

So through suggestive ads hinting at hookups through driving, Didi pushed Hitch’s romantic possibilities. In a 2015 interview with the Chinese online portal NetEase, Ms. Huang compared Hitch cars to cafes and bars.

“It’s a very futuristic and very sexy scenario,” she told NetEase.

Today, that attitude looks careless and incompetent. Two female Hitch passengers in the past three months have been raped and killed by their Hitch drivers, according to the police. Now Ms. Huang is out of a job, Didi is pledging to overhaul its business, Chinese consumers are calling for a boycott and the internet industry is getting a much-needed reminder of the consequences of its actions.