The San Francisco and Los Angeles district attorneys have sent letters to rideshare companies Uber, Lyft and Sidecar claiming they are operating illegally and warning them that legal action could follow if they don’t make major changes. The two district attorney offices conducted a joint investigation into the ride-share companies and found a number of practices that violate California law. The district attorneys told all three companies that they misled customers by claiming their background checks of drivers screen out anyone who has committed driving violations, including DUIs, as well as sexual assault and other criminal offenses. Gascón wants the companies to remove all statements from their mobile apps, websites and other publications that imply their background checks reveal drivers’ complete criminal history. The district attorneys also told all three companies that their new shared ride service fares â€" in which individuals going the same way can hop in a car and pay their fares separately â€" are calculated in a way that violates state law.