I find it interesting that CM rides are hassled by the authorities but not ROS rides.
I have participated in several ROS rides with 50 or more participants. Riding two abreast, obeying traffic laws, and slowing traffic (although not intentionally). Not once did the police disrupt these rides.
I have also participated in CM rides (often with far fewer participants). I noted and almost palatable expectation of confrontation with the law during the ride. Many times those expectations came true.
I continue to wonder what the difference is between these two rides.
On the surface they are very similar yet apparently they are viewed differently by the authorities.