The various kinds of "urban dirt biking" aren't an enormous problem by themselves.

It's definitely a PITA, especially if they start disrupting traffic, and just critical mass their way through red lights and intersections until the group is gone.

But, if the group is intent on the ride itself as a means and the end, it's generally a moderate inconvenience. They're always moving.

The big problem is that those interested in any sort of a "street takeover" are starting to notice urban dirt biking, and are incorporating it into well defined strategies.

They see the inability of police to effectively enforce anything on UDB activity, as the swarm is unstoppable on the whole, and any individual can easily cut between vehicles, buildings, sidewalks, and pass through or over many obstacles a car cannot.

Radical Leftist protestors have begun to employ dirt bikes and quad ATV's. They use them as scouts. And as skirmishers and a rapid-reaction security element.

The "regular person" is already at a huge practical and legal disadvantage if they get into a conflict with such a group. Whether it's actual ideological opposition, or they're just angry & frustrated at the inconvenience, or fall for provocation intentionally looking to manufacture an "enemy" at the planned event.

The person is outnumbered. They may also be vulnerable with family in the car. They're identifiable while the protestors/rioters are not. And any extreme force, like getting shot by someone with a CCW, rammed or run over, the group dynamics are intentionally fishing for it, hoping to create martyrs for the cause.

And now the protest/riot group can employ dirt bikes & ATV's as a roving, flexible, and quick reacting force that can fight with anyone, provide interference & distraction to law enforcement, and melt away quickly & easily avoiding arrest & prosecution. Which encourages like-minded people to step up fir the mayhem, because they perceive a risk/reward ratio skewing in their favor.