Thousands of people across the United States poured into the streets this week to protest the Trump administration's immigration policies, joining a nationwide wave of resistance that began in Los Angeles. One of the most widely shared images from the city, where federal authorities have sent almost 5,000 active-duty Marines and National Guard members, is of five Waymo robotaxis that were vandalized and set on fire. The incident has become one of the most recognizable symbols of the demonstrations so far, and prompted Waymo to temporarily shut off service in several parts of the city as well as in San Francisco on Monday. The charred Waymo cars have also raised fresh questions about what kinds of technology authorities can use to surveil protestors and potentially collect evidence to make arrests. According to Waymo's website, its latest driverless cars have 29 external cameras, providing "a simultaneous 360 view around the vehicle," as well as an unknown number of internal ones.