Not everyone is in love with the idea of autonomous vehicles and Waymo, formerly known as Google’s self-driving car project, is learning about it firsthand, as a slew of their test vehicles have come under attack.

Waymo vans on the road in Arizona have had tires slashed and their safety drivers have had weapons pointed at them at least 21 times in the last two years, and police believe the incidents are likely under-reported. Theories as to why vary from people being afraid of the technology to those who may fear losing their jobs when self-driving cars start taking to roads around the world.

Read about it in Newsweek.