Are you really that naive? This is what cops are there to do at protests.
Let me ask you a question. If a Police official tells his subordinates to search every black and latino age 14 to 21 do you consider them a criminal? Do you consider a cop a criminal if he sees and heres something like that and carries out his job as told and doesnt say anything?
Here is an example of what honest cops do when they see illegal activity.
I hope you run across a police officer who needs an arrest to meet his quota since your head is so far up their ass.
edit - almost forgot. I do not own my body because I can be arrested for smoking a joint in my own home. What I put into my body is my business and I believe Roe v Wade establishes that we have that privacy of our own body. How can someone have the right to kill a fetus inside their body but not smoke a joint? These same officers you weep for are the same ones I fear throwing a flash bang into my house in the middle of the night and murdering me because I inadvertently make a wrong movement while highly disoriented. Then the ones that murder me get a medal and claim they are justified in murdering me because I made a sudden movement. The way I see it I am a little safer now that theres a few less thugs off the street.