"If they don't like it they shouldn't come," said David. "They're murderers. I want them to feel uncomfortable. I want them to feel embarrassed. I want them to feel ashamed."
And off they went, armed with the addresses of the hotels where delegates to the Republican convention are staying, and mouthfuls of anarchist invective, to cause as much disruption as possible.
In contrast to the orderly march by hundreds of thousands of demonstrators on Sunday, yesterday was billed as a series of "guerrilla actions" organised by a loosely bound anarchist collective, A31.
"We'll transform the streets of New York city into a forum of resistance and debate," its website said.
The events were due to culminate last night in a march on Madison Square Garden, the site of the convention, with the prospect of many arrests.
Another protester, Simon, said: "We're targeting the delegates, the funders and the convention itself. I'll be surprised if there aren't 1,000 arrests just today."
So they started early, protesters in pig-snout masks at the breakfast given by the oil company Halliburton for Texan Republicans.
They threw fake $100 notes featuring a sneering picture of the vice-president, Dick Cheney, in the air and branded the company Hallibacon, accusing it of war profiteering.
Mr Cheney was once the chief executive of Halliburton, which has recently won huge contracts for work in Iraq. "We love money. We love war. We love Cheney even more," they chanted.
Just over an hour later, in Wall Street, demonstrators near the New York Stock Exchange tied coloured ropes around lampposts to block the traffic. There were 23 arrests. Another six protesters were arrested for wearing masks in a Harlem subway station, the authorities said.
"I may end up with a felony charge, I might have my head cracked open, but it will be worth it for democratic change," said David Solnit, who is with the "code orange" group affiliated to the A31 coalition.
Almost 600 people have been arrested since Thursday. On Monday a plainclothes police officer was taken to hospital with "serious facial trauma".
Yesterday Thomas Frampton, 21, a Yale University student, was charged with assaulting secret service officers while trying to get into Mr Cheney's box seat at the convention.