On busy streets outside bars or clubs, people often hop into a car without a second thought. But the killing of Samantha Josephson, a 21-year-old college student in South Carolina who was stabbed to death after getting into a car she mistook for her Uber last weekend, has brought national attention to a rash of kidnappings, sexual assaults and robberies carried out largely against young women by assailants posing as ride-share drivers.

There have been at least two dozen such attacks in the past few years, according to a tally of publicly reported cases, including instances where suspects have been charged with attacking multiple women. In Connecticut, a man was arraigned last week on charges that he kidnapped and raped two women who believed he was their ride-share driver. In Chicago, prosecutors said a man who posed as an Uber driver sexually assaulted five women, climbing into the back seat and pinning them down.

These attacks turn a simple mix-up into a nightmare, showing how easily bad actors can exploit the vulnerabilities of a ride-sharing culture that so many people trust to get them home safe.