What group did Uber use drones to target in its one-time marketing effort in Mexico City?

As part of Uber's big push of UberPOOL in markets across Latin America, the ride-sharing company deployed drones over cars stuck in traffic that "urged" drivers not to drive alone. “Driving by yourself?” some read in Spanish. “This is why you can never see the volcanoes." The explanation is that the smog that often hovers over the mega-city obscures two nearby peaks, MIT Technology Review reported.

Don't worry, though, sign-toting drones hovering above your windshield won't be a regular event. An Uber spokesperson told Business Insider that the drones were just a one-time occurrence, they only flew around for a matter of minutes and the company has no plans to try it out in another city anytime soon.