Cham Han walked out of a grocery store's air-conditioned quiet into the deafening chaos of a picket line rally.

Dozens of locked-out workers and union supporters marching at an Albertsons in Oxnard yelled as one at the 57-year-old Korean-American who shops at the stores that carry what she wants.

"Shame on you! Shame on you!"

The gray-haired neighbor Han recruited because she was scared to break the picket line alone rolled far ahead with a cart of chicken, broccoli and tri-tip. The shouts subsided before Han caught up, but the impact rang in her ears.

"I'm kind of confused," she said, her emotions percolating in a stream-of-consciousness rant. "We've got to eat. I don't care. I got to eat."

As the grocery store strike pushes through its third week, picket lines are propelled by simple but fierce emotions. Strikers want better contracts. Shoppers want groceries. Replacement workers want jobs.

The conflicting motivations pool into separate reservoirs like oil and water at most picket sites. The tension is tangible, but separation and common sense minimize ugly confrontations.

Sometimes, however, there is stirring and mixing and conflicts that leave each side feeling as if others have gone too far.

"They're over the line," Han said at the far end of the parking lot more than a week ago. "This is too much."

Some pickets agreed with her. They blamed the offending chant on a rally that bolstered their numbers with people from other unions. They fear "shame on you" will chase shoppers away forever and wound the industry that pays their wages.

"I just don't like the sound of it. It's disrespectful," said picketing cashier Eileen Lutizetti. "I kept saying, 'People let's not say that. Please.' "

The stakes shape how other strikers and locked-out workers view what is appropriate and what is not. They're living on $100 to $300 a week in order to fight for benefits and security they believe are being stolen from them. They feel their only weapon is to keep people out of stores and make executives feel the squeeze.

A little shouting, a little guilt, do not seem out of line. So even before Lutizetti finished her call for respect and dignity, another picket spotted a customer coming out of the store. "Shame on you," the demonstrator chanted, treating the words like a birthday present.

"I love it. I think it's great," she said, gesturing toward the shoppers. "These people need to understand what we're fighting for."

Public shamings are a rarity. Though the two sides haven't even been talking, there may be one point of agreement. Picket sites have been relatively well-controlled. Of course, a union official credited strike leaders for the conduct, while an Albertsons spokeswoman explained store directors are keeping lines of communication open to strikers and reminding them to respect customers.

Police said they have received isolated reports of alleged conflicts, ranging from tires slashed and cars scratched at an Ojai store to someone spraying pickets with window cleaning fluid in Port Hueneme. Though Ventura police officials said their calls were dwindling as the strike continued, they offered one strange nugget: a person in a picket line who loaded a replica .50-caliber machine gun in a pickup painted like a World War II vehicle. Officers responded and the model, apparently a symbol of strike as war, was stowed.

The strike and lockouts have turned store parking lots into roller coasters that dip and climb depending on the mix of personalities. A woman who crossed a picket line in midtown Ventura said she was surprised strikers dropped everything to help her when her 18-month-old child became ill. But at a store in downtown Ventura, complaints about a customer being harassed caused a Vons official to ask a landlord to remove pickets from the shopping center.

Such conflicting reports are the norm. Pickets hug some customers who they've known for years but cross the line because they don't know where else to get milk for the baby. Other times in other locations, they are accused of locking horns like battling rams.

"They were nasty and cursing at me," said Debby Brown of Simi Valley, remembering a trip to a Simi Valley store early in the strike.

Brown, a church administrator, has since found another store where she shops in relative peace. It bothers her to hear pickets talk of their personal friendships with their customers.

"I don't know of any of my neighbors and friends that scream and yell at me," she said.

One finger isn't peace

The dynamics are too complex to paint pickets as abusers. At a Vons in Thousand Oaks, shopper Lori Servin of Somis challenged strikers to explain their side as she left the store. She told them the union was "blowing smoke up their rear ends."

After leaving the picket line, Servin said she read the contract. The unions should sign; the employees should go back to work.

"I just think they're stupid... They're sheep," she said.

Pickets praised the customers who have honored their lines and said they understand that some people have made a different choice. They said most people who pass by their pickets do so quietly, some even offering apologies.

But sometimes it feels that as owners and replacement workers slug them in the face, customers are taking shots at their gut. They said they've been flipped off, cursed at and pelted with trash.

"Yesterday, I started crying because people don't care about our feelings," said Lolhy Salinas, picketing in Camarillo during the strike's second week. The emotion was triggered by a motorist who yelled "get a job."

For obvious reasons, frustrations often boil quicker the longer a strike goes on, said Teamsters administrator Dennis Shaw. He helped organize rallies, like the one held at Albertsons in Oxnard during the strike's second week, to show support for the United Food and Commercial Workers.

"It's pretty much softball," he said after the Albertsons demonstration, comparing the supermarket strike with a Teamsters walkout. "We're much more verbal, much more aggressive."

Teamsters confront line-breakers one-on-one. Union officials can't and don't condone pushing or shoving, but sometimes emotions get out of control.

"Those things do happen," Shaw said.

Legal lines of conduct seem as difficult to discern as the ethical standards. Obviously, violence crosses the line, but verbal communication is a gray area. An attorney with the National Labor Relations Board said statutes offer some guidelines of how strikers and replacement workers interact but largely don't address conflicts with customers. She said a judge might have to decide whether actions are intended to coerce or restrain people's movement.

Gilbert Siegel, an emeritus professor at USC who studies labor relations, asserted public shaming is a clear violation, ethically and legally.

"You can't block their way. You can't shout at them. You can't intimidate them," he said.

But a strike is about stopping business. And you stop business in a grocery store by convincing shoppers not to shop, said Kent Wong, a former union attorney who is director of the UCLA Center for Labor Research and Education.

Volume is a tool.

"I cannot imagine any court of law saying that would constitute any violation," Wong said of the "shame on you" chant. "That's protected free speech. People have the right to shout back."

Katie Quan, chairwoman of the Center for Labor Research and Education at UC Berkeley, finds it hard to feel sorry for the customers. They decided to cross the picket line.

"It's a decision they make and shoppers should live with the consequences," she said.

But customers talk about consequences too. At the Albertsons in Oxnard, a Hispanic man blistered by the mass "shame on you" struggled to express his reaction in English.

"No more coming here," he said.

Picking at wounds

After pickets and union supporters at the Ventura Road Albertsons rained shoppers with their chants, they spotted a replacement worker.

"Scab, scab, scab," they yelled in an angry chorus. They lurched into a second verse. "AFL-CIO, all the scabs have got to go."

The word is flung around as casually as a Frisbee.

"It's what they are," said Ellen Anreder, spokeswoman for the United Food and Commercial Workers. "If they can't live with being called the appropriate name, they should get a real job."

She was just getting started.

"These are the scum of the earth who are willing to be opportunistic and steal jobs from union workers who are fighting to protect their future. What kind of human being would do that? I shudder to think."

Ask Anreder if she would yell "scab" at a replacement worker. No, she answered. She doesn't like name-calling.

Some pickets in Ventura County said replacement workers flip them off and taunt them about money. For their part, some strike-breakers said they were unemployed and needed money. They said they're not replacing the pickets, just baby-sitting their jobs.

"They pay me too good not to do it," said Rich Allen of Camarillo.

For that, they are called losers and scabs. They said some of their co-workers have had tires slashed and cars scraped.

Some on both sides opt for the oil-and-water thing.

"We know we don't like each other," said Suzanne Helmer, a locked-out worker in Simi Valley. "I try to avoid them. Trust me, they try to avoid us... They kind of run to their cars to go home and we just kind of stare at them but there's no name-calling."

The animosity is not absolute. Some strikers said replacement workers are doing what they feel they must, just like the pickets. And inside a Ventura store, temporary worker Marguerita Martinez said she hasn't been harassed at all.

"They (pickets) say the store looks clean and we're doing a good job," she said.

Knotty relationships

The most complex relationship may involve striking employees and nonunion store directors. They have worked side by side, sometimes for many years. Now the directors are in the store and the workers are marching and chanting outside.

In some cases, a bond remains. Hang out at picket sites and strikers talk of how directors come out to talk or, early in the strike, to deliver cold water.

Late Monday afternoon, several locked-out workers at an Albertsons in Simi Valley decided not to talk to a newspaper reporter. "He'll eat you up like a Pac-Man," one man said to a colleague who consented to an interview.

They called a store director from inside the market. She asked the reporter to leave, emphasizing she was acting on behalf of the pickets who were still her associates. She stayed at the line for several minutes, laughing and chatting.

Reports of the incident set off union spokeswoman Anreder. Store directors understand pickets who talk to reporters will only help the public understand the union's cause, she said. Managers use friendships as a wedge to make the pickets know how much they're needed. They want them to drop their signs and go back to work.

"There's a lot of psychological warfare going on here," she said.

Several store directors said they couldn't give interviews. But Lilia Rodriguez, a spokeswoman for Albertsons, scoffed at the suggestion of ulterior motives.

"That's ridiculous," she said. "This is a company where store directors are very close to their employees."

When managers at a Vons in Ventura come out to see how strikers are doing, picketing pharmacy tech Sharon Martinez doesn't question their motives.

"When we get back in there we all have to work together," Martinez said, thinking of all the issues her bosses are facing during the strike. "I feel real sorry for them."