At the Charles Street corner of the Boston Common, there were maybe 150 young people Sunday night-Monday morning at 12:30 a.m.--all of them breaking the law. The curfew on the Boston Common, set a month ago and liberalized a week ago, is midnight. On Saturday, 65 hippies had been arrested for defying the curfew, and Sunday looked like more of the same.

There was the usual air of informality--a woman breastfeeding her baby, a couple of small groups formed around guitars, some people standing, some sitting, some rolling around in lovelocked pairs, and some sleeping.

Then, at a little before 1 a.m., people started to gather in a crowd for a meeting. Maybe 50 people sitting, and another 25 standing in a circle around them. They began to talk about The Man--the police--coming to get them, and what to do about it. The consensus of the group seemed to be for a symbolic march to the local jail with a demand to be arrested, or if not that, simply sitting there and allowing the police to remove them.

Then a tall, slender man, with side-burns and a wide white hat, entered the discussion. Standing on the rim of the circle, he towered over most of the others. He was from New York, a member of the "Up Against the Wall, Motherfuckers," a rather militant SDS chapter on the lower cast side of New York City.

He began to talk about mobile tactics, about moving one step faster than the police, about scattering and re-grouping, "because movement is life, man." When they come, take to the side streets. If it looks like one cop has someone caught, everyone else converge on The Man, and he'll let your comrade go. Keep loose, keep moving. The man can't run as fast as hippies.

In the circle, some people listened attentively to the tall speaker, occasionally chipping in an anti-cop line. Others buzzed in small subgroups of their own. A few crowded around a small Negro boy, perhaps 12 years old, who was explaining why he was there.

"Movement is life, man you gotta keep ahead of The Man," the New Yorker repeated. "The Man has his weapons, we've got to develop our own, and mobile tactics is our best weapon."

Gradually, almost imperceptibly, the New Yorker was hypnotizing the crowd. He had the Conch, and he was not to release it. The side discussions broke up, and now everyone was listening to the mobile tactician. Some began asking concerned questions: "What happens when the cops catch us while we're running?"

"The Man won't catch us; he's fat. He eats too much starch. All day long, he eats starch, and then finds out he can't keep up with a hippie. He takes a good long look at himself in the mirror, and realizes that he can't keep up with a hippie."

"Which way do we scatter when they come?"

"We can't worry about specifies now. We first have to decide if this is the way we're gonna handle The Man."

The New Yorker began to relate tales from the Lower East Side, where mobile tactics had been used effectively. If the cops caught up with someone on a side street, he said, everyone nearby would converge screaming on that cop," and he'd let our boy go, let me tell you."

The circle, which 20 minutes earlier had been thinking primarily about peaceful protest, was now talking about military strategy for the policeman-enemy. There was still opposition, of course. One bearded man, Leonard Wolfe, who had supported the march to the jail, argued in a half-whisper with Mark Dyen, of Harvard SDS, who supported mobile tactics.

Dyen, who has short hair and dresses straight, looks like a political organizer, and distinctly unlike a hippie. Most of the real hippies, it seemed, were not even sitting in that circle--they were 50 yards away, just singing and playing the guitar. You could tell that they would go home peacefully when the cops came. They weren't into this thing of fighting cops.

But in the circle, mobile tactics was winning the day. Only once did it appear that the tail New Yorker's authority would be questioned--when a black man of the fringe of the circle called out "Where are you from?"