Police fear the worst may not yet be over.
"It's gonna be a very long night," said Mike McCormack, head of the Toronto Police Association.
He said fresh officers are poised to take the night shift.
That no officers or members of the public were seriously hurt is a silver lining to today's events, Mr. McCormack said. He expects that at some point, police leaders will sit down and look at whether protester countermeasures were adequately planned by police.
But "at some point it becomes a logistical nightmare," he said.
Mr. McCormack said that the radical protesters who attacked police cruisers and police headquarters were absolutely "disgusting" -- unlike anything he has seen in two decades of being a cop.
He said he witnessed many attacks on police as he wandered the downtown core.
"I walked Yonge Street from Dundas Street to College Street," he said. "Windows broken, looting … what's this got to do with the G8/G20?"
"It's not about the issues," he said. "It's about hooliganism."
Toronto Police Chief Bill Blair's boss said that, in time, he would welcome an account of what went right and what went wrong during the G20 weekend.
"I'm sure board members would be interested in hearing from the chief," said Alok Mukherjee, the civilian chair of the Toronto Police Services Board. "We'll have to give Chief Blair some time to make his assessment."
Mr. Mukherjee was laudatory of the police response to protesters. "The bottom line was that nobody would be able to breach the fence," Mr. Mukherjee said, before adding that "I was taken by surprise, like many Torontonians, to see the sight of police vehicles that were set on fire."
He said that the police squad cars - and at least four are known to have been burned by radical protesters beyond repair - cost about $25,000 each, without computers and other equipment.
But "all of our properties are insured," said Mr. Mukherjee.
Asked whether he was worried that Toronto Police may be eventually exposed to lawsuits from business owners alleging their property was not adequately protected, Mr. Mukherjee said, "I can't respond to that. We'll have to wait and see."