I can guarantee you that those who carried out the public destruction and the intimidation of the populace don't give one shit about what goes on in the rest of the world. On the contrary, they use the cover of what you call "legitimate concerns" as an excuse for their violence. Some bunch of heroes. I'm pretty sure that the vast majority of these so-called "anarchists" have not had to suffer from extreme poverty of a lack of clean drinking water, but they use the existence of those things to legitimate their mass acts of vandalism. In the end, they achieve absolutely nothing positive or worthwhile for anyone - other than satisfying their selfish desire to cause damage and terrify others.
You also appear to be oblivious to the fact that it is the violent "anarchist" protesters who undermine reasonable forms of expression that can give voice to legitimate causes during these summits. You are so quick to condemn governments that you forget to recognize that the failure lies with those who can't express a legitimate reasoned thought, but opt instead to smash property and intimidate people. What we are left with is a situation where protest - the legitimate right to public free expression - comes with the anticipation of violence. In doing so, the entire idea of civil protest suffers because these violence-prone individuals have directly linked their destructive acts to protest activities. These individuals are true parasites. They feed off the good intentions of reasonable persons wishing to draw attention to a specific issue, they commit their callous crimes, and in doing so they undermine reasoned protest actions.