I do not favor acts of government which constrain free speech. I think that this could be handled better.
I don't see April 15th tax protestors doing the things that the G-8 yahoos do. The criminal mischeif is clearly the issue. It also sticks in mind that whenever somebody wants to hold a demonstration in most major cities in the US, they are required by the city to obtain some form of 'protest permit'. This chafes me, because it amounts to requesting the government's permission to peaceably assemble. Permission, can always be denied.
The practical side of it is that cities are obligated to protect the interests of their citizens. A bit of advanced warning that there are going to be thousands of folks, many from out-of-town showing up, most or all of them angry about something, isn't an unreasonable thing to ask. So I am of two minds on the issue of protest permits.
As much as I dislike this bunch of destructive cretins, they are within their rights to peaceably assemble to express their views. When you get a bunch with a track record like theirs, I am not sure what the answer is. There will be trouble. How the city handles it, ultimately remains to be seen. I don't like laws that set bad precedent. But I also don't like groups who willingly and knowingly abuse their rights. On the balance, the first duty of government is to protect the Constututional rights of its citizens, so I disagree with the passage of laws that constrain free speech. I think that it'd have been wise to handle this differently.
Lots of coppery in evidence to deal with the destructive types, would be my first inclination. I am intrigued also by another poster's suggestion that groups who are going to have these kinds of protests put up a bond or financial guarantee against damages and injuries caused, giving them an incentive to police their own. Discuss?