Cars already take over the roads, why shouldn't people try to take them back?

My local bicycle ride that blocks intersections while the riders go through is known and protected by the police -- the legal theory is that if the front of a vehicle entered the intersection on a green light, the "vehicle" can continue through the intersection if the light changes. And a group of people riding bikes as one unit is considered one vehicle.

A bike ride with many people in it is considered a single vehicle if they all ride together with no big gaps through the intersection. There are volunteers called "corkers" who will stand in front of the intersection to clearly signal to motor vehicles that it is not safe to enter the intersection yet. They're trained in deescalation in case someone is really upset that they had to wait an extra minute or two on a Friday night.

Here's an article if anyone is interested.

https://grist.org/cities/bike-party-a-fresh-new-way-to-take-back-the-streets/