(NewsNation) — An activist group in San Francisco is on a mission to put the brake on driverless cars, claiming the vehicles are unsafe, but the vehicle companies say it’s the group’s actions that are unsafe.

A secretive group called Safe Street Rebel has been disabling driverless vehicles by putting orange traffic cones on their hoods. This disrupts the sensors and immediately disables the vehicle.

“People are selling it like the future of humanity, robot cars, and then no, a simple low-tech traffic cone and it disables it, at least temporarily,” said an anonymous Safe Street Rebel.

Each “coning” incident causes the AV to immediately stop and initiate the hazard lights. A human technician must then respond to reset the vehicle.

“What we want to do is develop tactics against car dominance in all of its forms,” the “Rebel” said.

Hundreds of AVs, or autonomous vehicles, run by Waymo and Cruise are currently on the roads in San Francisco, Phoenix and Austin. These companies have logged millions of miles with tens of thousands of safe and successful rides.

The so-called “cone campaign” is aiming to steer AVs off the roads following recent incidents in which the vehicles have stalled and blocked traffic, hindered first responders and even hit and killed a dog.

Safe Street Rebel believes this system is dangerous and discourages the use of public transit. The group is encouraging more “coning” ahead of a hearing Thursday where the California Public Utilities Commission is expected to approve the expansion of AV operations.

The group describes itself as a decentralized group of activists.

“We want to either have AVs not on the city streets at all, or at least very limited. We see these as a threat and not a complement to more environmental mobility solutions like public transit and active mobility,” a member of the group said.

In separate statements, both Waymo and Cruise touted the safety of their systems, both expressing that coning is dangerous and causes traffic backups.

Waymo calls the practice vandalism, warranting notification of law enforcement for unsafe interference.

“This is vandalism and encourages unsafe and disrespectful behavior on our roadways,” Waymo said in a statement.

A Cruise spokesperson says, “Intentionally obstructing vehicles gets in the way of those efforts and risks creating traffic congestion for local residents.”

Despite the rebel resistance, transportation engineer Kara Kockelman believes driverless technology will be the safer alternative in the future.

“There’s always a very healthy mix of different driving tendencies out there on the roadways,” Kockelman said. “Our current technology with a human in the driver seat isn’t cutting it and we expect to dramatically reduce crash rates from the self-driving vehicles because they’ve got eyes on every corner of that vehicle and really fast-acting technology.”

Now, ahead of the state hearing Thursday, the rebel group has declared a week of cones.