On a November day in 1999, Seattle police lost control of their city.

During a meeting of the World Trade Organization, protesters blockaded intersections, cut off delegates from the conference and rifled through local businesses, causing extensive damage. Police used rubber bullets and tear gas to control the crowd, but it took days to restore order.

A group of Twin Cities anarchists now is making similar threats against the 2008 Republican National Convention in St. Paul. But they also made threats against the 2004 conventions in Boston and New York, and little ever came of them.

The question is what to make of the anarchists? Are they for real? And how seriously should the city take their threats?

“We’ve learned lessons from others cities, including Boston and New York, including Seattle,” said Tom Walsh, a spokesman for the St. Paul Police Department. “We don’t simply think we can ignore the potential for a group of people to try to interrupt the convention by committing criminal acts. We feel we have a plan in place to deal with that.”

This month, the RNC Welcoming Committee, a group of self-styled anarchists, caused alarm when its Web site linked to an online plan for moving delegates to and from the Xcel Energy Center. The subsequent media coverage caused so much commotion, the Welcoming Committee’s Web site crashed.

The group differs from the Coalition to March on the RNC and Stop the War, which is organizing the main protest march on the convention, and its aims are broader. Rather than advocating an end to the war in Iraq, anarchists want an end to corporate globalization and, for some, a return to a more primitive lifestyle.

The anarchists say they won’t talk to “corporate media,” but one of the nation’s best-known anarchists is John Zerzan, a Eugene, Ore.-based author and host of Anarchist Radio. When contacted by phone, Zerzan said he regards the Seattle protest and riots as a success because they spotlighted anarchists’ antiglobalization message.

Zerzan — a confidant of Theodore Kaczynski in the mid-1990s while the Unabomber awaited trial — said anarchists want to end corporate domination of the planet and roll back technological advances. His new book is titled “Twilight of the Machines.”

Eugene-based anarchists were instrumental in the Seattle riots, and Zerzan does not back away from the methods. While he doesn’t condone violence against other individuals, he doesn’t see property damage as violent — “Certainly not corporate property,” Zerzan said.

Early in the 20th century, estimates of the number of anarchists in the U.S. ranged into the millions. As a group, they largely disappeared until the 1960s, when their numbers started to grow again.

They were thrust back into the national psyche during the WTO protests. “60 Minutes II” profiled the group, featuring Zerzam prominently in its report.

Jess Sundin of the Anti-War Coalition, part of the Coalition to March on the RNC and Stop the War, said the group has had discussions with the anarchists but only to make sure they don’t disrupt the march.

“They’ve made a commitment not to interfere,” Sundin said.

Much as St. Paul is doing, police forces in Boston and New York took the groups seriously.

Boston Police Superintendent Robert Dunford said he tracked the groups through their online postings and literature (which St. Paul is also doing), but their threatened disruptions never materialized.

“A lot of it was street theater. A couple of marches,” Dunford said.

“These groups, some of them are real and some of them are not,” he added. “You really don’t know.”

New York City Deputy Police Commissioner Paul Browne echoed that thought. “We took it seriously. Some of it was boasting, and some of it was real. You can’t always tell,” Browne said.

But New York did disrupt anarchist activities before they occurred. “There were attempts, but we were well aware of the attempts in advance,” Browne said.

He added: “In cases where violence was being planned, we had direct information about it even when it wasn’t published.”

Anarchists also held classes on less-menacing activities — how to disable a bus engine, for example.

“We were at those classes,” Browne said, declining to say whether the department used undercover officers or simply attended the meetings.

He also pointed out that New York hosted an anti-war march viewed as the largest in U.S. history — estimates range up to 1 million — with relatively few arrests. But law enforcement officials say it takes only a few people to disrupt the peaceful intentions of many.

So is the Welcoming Committee real? Will they cause havoc at the convention? At this point, it’s tough to say.

The group posted a YouTube video featuring people wearing bandanas over their faces and clad in black that walks the line between camp and menace.

It shows why determining the group’s intentions is difficult. At one point an anarchist lights a Molotov cocktail.

The flaming bottle is tossed over a fence and lands in a barbecue, where another anarchist waits, spatula in hand.

Another group of about 150 anarchists from the U.S. and Canada were in Wisconsin this week training for demonstrations at the Democratic and Republican conventions. The anarchists were attending four days of workshops in Waldo in Sheboygan County. Some of the workshops focused on strategies for the upcoming conventions.

The sessions were organized by the CrimethInc. Ex-Workers’ Collective, an underground group that has published anarchist texts such as “Recipes for Disaster: An Anarchist Cookbook.”

Anarchists generally do not conceal their intentions. What they plan to do is posted on the Internet and in literature handed out at left-leaning events. Some say they simply hope to inspire others to commit the acts they outline, without having to do it themselves. That’s why media coverage — despite the RNC Welcoming Committee’s stated aversion to mainstream media — is helpful to their cause.

“Every time you write a story about them, you give us a hard time,” Dunford said.

The Associated Press contributed to this report.

ONLINE

The RNC Welcoming Committee’s video is at youtube.com/watch?v=j6PLwOt0Bls.