The jump-happy group wasn't aware that this sport was not permitted in the area.
In fact, right when they were hooked onto their equipment and ready to make the jump, the cops descended on them. Seeing the equipment, the cops immediately figured out what they were up to and stopped them from attempting "the illegal".
The group was then told about the ban on the sport which is when they realised the gravity of the situation. The cops realised they were unaware of the law and just decided to let them off with a warning this one time..