That would constitute assault, and would merit use of force to stop the assault.
A guy riding a bicycle, even if he's in violation of some traffic code, does not merit the same sort force.
Would you recommend that cops billyclub jaywalkers? Would it matter to you if they were jaywalking under a Free Mumia banner or a Support our Soldiers banner?
When 100 bicyclists are conspiring together to disregard traffic lights and stop signs to engage in a “commute clog” civil protest, they are more than just being “rude”.
If asked to STOP by the officer (especially to be cited, even if one out of 100), the officer has the authority to take someone down by non-lethal force.
Have you ever seen them putting handcuffs on a drunk who is resisting? Someone who is trying to get up off the ground when they have been instructed to lie down?
Those marching under a banner would need a permit from the cities. Critical Mass considers their activities “without leadership” but like any flash mob, there is someone who takes the initiative to post a bulletin online or put a flyer on a wall.
Ever get bumped into by someone who wasn't looking where they were walking? Ever get bumped into by someone who wasn't looking (or caring) where they were riding their bike at 25 MPH?
If the flash mob decides to have a spontaneous marathon, then you can go after the jaywalkers with billy clubs. Rioters tend to be running anyway.
If their sole stated purpose is to irritate and inconvenience everyone else on a regular schedule, sure.
Next juvenile question?