1000s protest the Chicago NATO summit (CBS News) CHICAGO - Whatever NATO's ultimate withdrawal timetable from Afghanistan is, it won't be speedy enough for demonstrators outside the current summit in Chicago. Thousands of protesters walked the sweltering streets of Chicago on Sunday to vent their opposition to NATO and the government leaders meeting just a few hundred yards away. "We're spending $2 billion a week killing people who are very far away and really haven't don't anything to us," said protester Jeri Sparks. CBS News correspondent Dean Reynolds reports that as their chants echoed off the facades of downtown skyscrapers, a massive cordon of police - including SWAT teams - marked their every footstep and led them along their approved path. The ranks of the more violence-prone participants had been thoroughly infiltrated by undercover officers days ago, including three arrested last week who prosecutors accused of conspiracy to commit terrorism. NATO: Obama warns of "hard days" ahead in Afghanistan NATO commits to Afghanistan beyond 2014 NATO chief: "No rush for the exits" in Afghanistan There was also a cyber attack on the city of Chicago's website that lasted several hours. The hacker group which calls itself Anonymous claimed responsibility. "We are actively engaged in actions against the Chicago police department and encourage anyone to take up the cause," the hacker group said in a statement. But while some demonstrators were looking for trouble, for the most part the protests have been peaceful - something the city police superintendent noted amid the crowds along Chicago's lakefront. "You're seeing us facilitating peaceful protests, protecting people, providing for the public safety, while at the same time being intolerant of crimes being committed," said Chicago Police Superintendent Garry McCarthy. Hosting the NATO summit is a big deal for Chicago. The city's been on edge for days hoping the police and protesters could mingle peacefully. So far, that appears to be the case.