A dull office park near Virginia’s Dulles International Airport took on the sheen of a Hollywood thriller this week when an invitation-only cadre of global leaders gathered for a secretive meeting known as the Bilderberg conference.

Henry Kissinger and Bill Gates were chauffeured in. Fairfax County police established a security perimeter around the Westfields Marriott and prohibited a Washington Post photographer from snapping pictures from the public street.

Outside the barriers, dozens of protesters and conspiracy theorists – convinced that Bilderberg is a global cabal that runs the world – waved signs and shouted into a bullhorn.

“Honk if you hate the new world order!” they blared, hooting at drivers passing by. Fairfax County police have made three arrests for a variety of misdemeanor offenses such as obstruction of justice and disorderly conduct, a police spokesman said.

“This is the true power structure, the shadow government,” said Shawn Flinchbaugh, 29. The machinist from York County, Pa., stood outside the conference center clutching a handmade sign lettered “Bilderberg Scum.” “They say they don’t exist, but they do.”

According to its website, the Bilderberg meeting was organized by leaders from Western Europe and North America in the early days of the Cold War, and is named for the Dutch hotel where the first enclave was held in 1954. The current chairman of its steering committee is a French count. Others include the neoconservative scholar Richard Perle, the billionaire Peter Thiel, and financiers such as Roger Altman and Kenneth Jacobs, chairman and chief executive of Lazard.

About 120 people participate in “nearly three days of informal and off-the-record discussion about topics of current concern” in economics and foreign affairs, with the crisis in Syria, the euro zone and the U.S. presidential election likely taking center stage this time.

Attendees are encouraged not to discuss the proceedings, which fuels the secrecy concerns. Many adopt a Fight Club approach to answering questions afterward. In other words, the first rule is, you do not talk about Bilderberg.

Over the years, conspiracy buffs have embraced such notions that the group is behind the creation of the euro and meets to select the winners and losers in the U.S. presidential election — or at least endorse the candidate’s vice presidential pick. A speech by then Sen. John Edwards, D-N.C., during Bilderberg in 2004 helped cement his vice presidential bid.

Vin Weber, a Washington lobbyist and former Minnesota congressman who has been a presenter at Bilderberg twice, laughs at such talk. He recalled a vigorous disagreement over presidential politics at one Bilderberg meeting, with Obama supporter James Johnson advocating for his guy and former Bill Clinton adviser Vernon Jordan speaking up for Hillary Clinton.

“Everybody talks about this great conspiracy, but it’s really not. It’s fun to be able to talk about it,” said Weber, who is a Romney adviser.

So as the motorcades come and go, are they talking of Marco Rubio?

“Yesterday I saw three billionaires. These are the kingmakers. Whoever we see here is likely to be the vice presidential candidate,” said Mike Peachman, 24, a linguist from New York. He was keeping an eye out for Indiana Gov. Mitch Daniels, a scheduled presenter sometimes mentioned as a Romney vice presidential pick. (Also on the invitation list was Donald Graham, chairman of the board and chief executive of The Washington Post Co.)

Every once in a while a van with tinted windows would drive through the gate, and the crowd of protesters would chant “Scum, scum, scum!” as it sailed by. But then the sky darkened and severe thunderstorms came sweeping through, ruining everything. The timing couldn’t have been more perfect if the Lords of Bilderberg had arranged it themselves.