Yup. One of the turning points of the civil rights movement (way before it became perverted/inverted) was the images of peaceful protesters being attacked with bully clubs, dogs, etc. While one doesn't know exactly what would happen the key is to have as many cell phone cameras (and any others) documenting everything possible such as police (not a given enemy until proven as such), the size of the crowd, the strident but peaceful nature, the actions of counter-protesters, recording the media recording us, etc.
Cameras, cameras, cameras are so important. Oral testimony will never trump actual video evidence plus cell phone cameras can be uploaded to the web or an alternate server so that confiscation will not necessarily mean a video has been eliminated.
I think Chicago would be a key spot because of the corruption that sprung from there and moved to DC and headlined this mess and because Daley would probably copy, in a little lower key, the same actions his dad did 41 years ago. No need to do anything but show up with banners - Daley and goons would take care of the rest.
Really big mistake...especially in Chicago. If the media covered it at all it would be one protestor who sneezed and someone, not anyone who go beat up protesting. It would be used as propaganda to support their agenda.