Even though the effective symbol of their movement is a Phase II helmet with a cross through it, I think the "Stop Cloning Violence" sign indicates at least some awareness on the part of the anti-war faction that the clones themselves are not to blame. They're just tools (even fellow victims) whose construction and maintenance are hogging financial resources that should be going towards preventing the population falling into poverty; they're not the conscious oppressors of the people. It's not like the protesters are demanding the downfall of a "Clone Menace". The monument could be considered a perfectly valid target of ire, though. The relationship between mainstream society and soldiers over history has been an interesting one. It was commented around the time of the First World War that the problem with a bayonet was that a working man was found on each end. The clones, however, are not "of the people" in the same sense that a volunteer or conscripted army would be. Like the Janissaries of the Ottoman Empire, they're inherently separate from mainstream society. For an anti-war activist on Coruscant, this memorial might be considered commendable for recognising the lives of individual troopers, but it does effectively glorify the "alien" Grand Army, death in combat ("You will be remembered, Captain Gregor...") and the militarisation of the Republic. In Dark Lord, set immediately after ROTS, Palpatine explicitly cites the example of the clone troopers as one for the average citizen to follow. It's not likely that a clone would be opposed to such glorification. Gregor is willingly self-sacrificial after he gets his memories back. Even Fives justifies his insubordination in the name of the Republic. Rex... might actually turn out different, though. However, note that they're targeting the Jedi primarily. Like the clones, they're an "alien" element, but somehow they've attracted much more of the blame. According to SW.com, another sign wielded by the protesters claims that the Jedi are corrupt. The Jedi probably get most of the blame for the introduction of the clones and the clones themselves are recognised to be less responsible than others for the war named after them.