If we get civilians assaulting protesters, it will convey a slightly different image than police assaulting protesters, but still not a good one. It will convey to most Americans that Iowans -- the people -- are fascists.
As for any "therapeutic" effect you think it will have, please note that so far it has been rather dramatically ineffective. There is no reason to believe that Occupy is going to fold at a little rough treatment from Iowans when they haven't yet from New Yorkers, Oakland police, etc.