Two 15-year-old kids who were allegedly drinking alcohol in the San Francisco Bay Area and shooting water bead guns were detained by police on Monday, according to the San Mateo Police Department. This story of juvenile delinquency normally wouldn’t be particularly notable, except that the kids were in a Waymo and the cops say the robotaxi company called the authorities, leading to questions about what kind of surveillance passengers should expect in the emerging world of autonomous vehicles. “After calling us and stopping the car, we were able to safely remove both subjects and determined they were shooting Orbeez from the car as they sipped on afternoon libations while being chauffeured around town in the driverless vehicle,” the San Mateo Police Department wrote on Facebook. It’s unclear what the kids were targeting with their Orbeez guns, also known as gel blasters, which fire water pellets. But it prompted a Waymo employee monitoring the vehicle to call 911, according to NBC Bay Area. The Waymo monitor also “reported seeing a recoil,” according to the local TV news outlet.

“While there was some ingenuity to this scheme, toy guns, water guns, and BB guns all pose real dangers, especially to an untrained eye,” the police continued in their Facebook statement. “The simple handling of them can cause fear in passerby’s [sic] or to those who don’t get a good look. Shooting projectiles at speed can cause real damage. And lest not forget the underage drinking. All bad ideas today for these two.”