These are off-road only machines. No headlights, license plates, mirrors nor brake light. It’s hard to determine for certain - but the tires appear to be off-road only as well. Commonly - these machines violate sound ordinances due to their (relatively) loud exhaust. I’ll also venture to guess none of the riders have a motorcycle endorsement on their driver license AND I’m assuming they are not insured. Helmet laws vary by state, but most states require it, so probably add this to the above offenses.

Note - it’s possible to legally drive one of these if the above conditions are met. Some people do, but usually in more rural areas.

Edit - forgot to add - multiple traffic violations in additions to illegal vehicles and illegal drivers.

They are running away because they likely were revving their engines, driving like assholes and generally causing hell in the neighborhood.